蟻群算法(ant colony optimization, ACO),又稱螞蟻算法,是一種用來在圖中尋找優化路徑的機率型算法。它由Marco Dorigo於1992年在他的博士論文中提出,其靈感來源於螞蟻在尋找食物過程中發現路徑的行為。蟻群算法是一種模擬進化算法,初步的研究表明該算法具有許多優良的性質.針對PID控制器參數優化設計問題,將蟻群算法設計的結果與遺傳算法設計的結果進行了比較,數值仿真結果表明,蟻群算法具有一種新的模擬進化優化方法的有效性和應用價值。
預期的結果:
各個螞蟻在沒有事先告訴他們食物在什么地方的前提下開始尋找食物。當一只找到食物以后,它會向環境釋放一種信息素,吸引其他的螞蟻過來,這樣越來越多的螞蟻會找到食物!有些螞蟻並沒有象其它螞蟻一樣總重復同樣的路,他們會另辟蹊徑,如果令開辟的道路比原來的其他道路更短,那么,漸漸,更多的螞蟻被吸引到這條較短的路上來。最后,經過一段時間運行,可能會出現一條最短的路徑被大多數螞蟻重復着。
原理:
為什么小小的螞蟻能夠找到食物?他們具有智能么?設想,如果我們要為螞蟻設計一個人工智能的程序,那么這個程序要多么復雜呢?首先,你要讓螞蟻能夠避開障礙物,就必須根據適當的地形給它編進指令讓他們能夠巧妙的避開障礙物,其次,要讓螞蟻找到食物,就需要讓他們遍歷空間上的所有點;再次,如果要讓螞蟻找到最短的路徑,那么需要計算所有可能的路徑並且比較它們的大小,而且更重要的是,你要小心翼翼的編程,因為程序的錯誤也許會讓你前功盡棄。這是多么不可思議的程序!太復雜了,恐怕沒人能夠完成這樣繁瑣冗余的程序。
然而,事實並沒有你想得那么復雜,上面這個程序每個螞蟻的核心程序編碼不過100多行!為什么這么簡單的程序會讓螞蟻干這樣復雜的事情?答案是:簡單規則的涌現。事實上,每只螞蟻並不是像我們想象的需要知道整個世界的信息,他們其實只關心很小范圍內的眼前信息,而且根據這些局部信息利用幾條簡單的規則進行決策,這樣,在蟻群這個集體里,復雜性的行為就會凸現出來。這就是人工生命、復雜性科學解釋的規律!那么,這些簡單規則是什么呢?
下面詳細說明:
1、范圍:
螞蟻觀察到的范圍是一個方格世界,螞蟻有一個參數為速度半徑(一般是3),那么它能觀察到的范圍就是3*3個方格世界,並且能移動的距離也在這個范圍之內。
2、環境:
螞蟻所在的環境是一個虛擬的世界,其中有障礙物,有別的螞蟻,還有信息素,信息素有兩種,一種是找到食物的螞蟻灑下的食物信息素,一種是找到窩的螞蟻灑下的窩的信息素。每個螞蟻都僅僅能感知它范圍內的環境信息。環境以一定的速率讓信息素消失。
3、覓食規則:
在每只螞蟻能感知的范圍內尋找是否有食物,如果有就直接過去。否則看是否有信息素,並且比較在能感知的范圍內哪一點的信息素最多,這樣,它就朝信息素多的地方走,並且每只螞蟻都會以小概率犯錯誤,從而並不是往信息素最多的點移動。螞蟻找窩的規則和上面一樣,只不過它對窩的信息素做出反應,而對食物信息素沒反應。
4、移動規則:
每只螞蟻都朝向信息素最多的方向移,並且,當周圍沒有信息素指引的時候,螞蟻會按照自己原來運動的方向慣性的運動下去,並且,在運動的方向有一個隨機的小的擾動。為了防止螞蟻原地轉圈,它會記住最近剛走過了哪些點,如果發現要走的下一點已經在最近走過了,它就會盡量避開。
5、避障規則:
如果螞蟻要移動的方向有障礙物擋住,它會隨機的選擇另一個方向,並且有信息素指引的話,它會按照覓食的規則行為。
6、播撒信息素規則:
每只螞蟻在剛找到食物或者窩的時候撒發的信息素最多,並隨着它走遠的距離,播撒的信息素越來越少。
根據這幾條規則,螞蟻之間並沒有直接的關系,但是每只螞蟻都和環境發生交互,而通過信息素這個紐帶,實際上把各個螞蟻之間關聯起來了。比如,當一只螞蟻找到了食物,它並沒有直接告訴其它螞蟻這兒有食物,而是向環境播撒信息素,當其它的螞蟻經過它附近的時候,就會感覺到信息素的存在,進而根據信息素的指引找到了食
問題:
說了這么多,螞蟻究竟是怎么找到食物的呢?? 在沒有螞蟻找到食物的時候,環境沒有有用的信息素,那么螞蟻為什么會相對有效的找到食物呢?這要歸功於螞蟻的移動規則,尤其是在沒有信息素時候的移動規則。首先,它要能盡量保持某種慣性,這樣使得螞蟻盡量向前方移動(開始,這個前方是隨機固定的一個方向),而不是原地無謂的打轉或者震動;其次,螞蟻要有一定的隨機性,雖然有了固定的方向,但它也不能像粒子一樣直線運動下去,而是有一個隨機的干擾。這樣就使得螞蟻運動起來具有了一定的目的性,盡量保持原來的方向,但又有新的試探,尤其當碰到障礙物的時候它會立即改變方向,這可以看成一種選擇的過程,也就是環境的障礙物讓螞蟻的某個方向正確,而其他方向則不對。這就解釋了為什么單個螞蟻在復雜的諸如迷宮的地圖中仍然能找到隱蔽得很好的食物。
當然,在有一只螞蟻找到了食物的時候,大部分螞蟻會沿着信息素很快找到食物的。但不排除會出現這樣的情況:在最初的時候,一部分螞蟻通過隨機選擇了同一條路徑,隨着這條路徑上螞蟻釋放的信息素越來越多,更多的螞蟻也選擇這條路徑,但這條路徑並不是最優(即最短)的,所以,導致了迭代次數完成后,螞蟻找到的不是最優解,而是次優解,這種情況下的結果可能對實際應用的意義就不大了。
螞蟻如何找到最短路徑的?這一是要歸功於信息素,另外要歸功於環境,具體說是計算機時鍾。信息素多的地方顯然經過這里的螞蟻會多,因而會有更多的螞蟻聚集過來。假設有兩條路從窩通向食物,開始的時候,走這兩條路的螞蟻數量同樣多(或者較長的路上螞蟻多,這也無關緊要)。當螞蟻沿着一條路到達終點以后會馬上返回來,這樣,短的路螞蟻來回一次的時間就短,這也意味着重復的頻率就快,因而在單位時間里走過的螞蟻數目就多,灑下的信息素自然也會多,自然會有更多的螞蟻被吸引過來,從而灑下更多的信息素……;而長的路正相反,因此,越來越多地螞蟻聚集到較短的路徑上來,最短的路徑就近似找到了。也許有人會問局部最短路徑和全局最短路的問題,實際上螞蟻逐漸接近全局最短路的,為什么呢?這源於螞蟻會犯錯誤,也就是它會按照一定的概率不往信息素高的地方走而另辟蹊徑,這可以理解為一種創新,這種創新如果能縮短路途,那么根據剛才敘述的原理,更多的螞蟻會被吸引過來。
/*ant.c*/ #define SPACE 0x20 /*按鍵定義*/ #define ESC 0x1b #define ANT_CHAR_EMPTY '+' #define ANT_CHAR_FOOD 153 /*攜帶食物的螞蟻*/ #define HOME_CHAR 'H' #define FOOD_CHAR 'F' #define FOOD_CHAR2 'f' #define FOOD_HOME_COLOR 12 /*紅色*/ #define BLOCK_CHAR 177 /*障礙物*/ #define MAX_ANT 50 /*螞蟻數量*/ #define INI_SPEED 3 /*速度半徑為3*3*/ #define MAXX 80 /*活動空間為80*23格*/ #define MAXY 23 #define MAX_FOOD 10000 /*最大食物量*/ #define TARGET_FOOD 200 /*需要采集回家的食物量*/ #define MAX_SMELL 5000 /*最大信息素*/ #define SMELL_DROP_RATE 0.05 /*信息素釋放率*/ #define ANT_ERROR_RATE 0.02 /*螞蟻犯錯率(創新率)*/ #define ANT_EYESHOT 3 /**/ #define SMELL_GONE_SPEED 50 /*信息素消失速度*/ #define SMELL_GONE_RATE 0.05 /*信息素消失比率*/ #define TRACE_REMEMBER 50 /*螞蟻記憶力*/ #define MAX_BLOCK 100 /*最大障礙物個數*/ #define NULL 0 #define UP 1 /*方向定義*/ #define DOWN 2 #define LEFT 3 #define RIGHT 4 #define SMELL_TYPE_FOOD 0 /*信息素類型定義*/ #define SMELL_TYPE_HOME 1 #include "stdio.h" #include "conio.h" /*getch函數需要此頭文件*/ #include "dos.h" #include "stdlib.h" #include "dos.h" #include "process.h" #include "ctype.h" #include "math.h" void WorldInitial(void); /*環境初始化函數*/ void BlockInitial(void); /*障礙物地圖初始化*/ void CreatBlock(void); /*產生障礙物地圖*/ void SaveBlock(void); /*保存障礙物地圖*/ void LoadBlock(void); /*載入障礙物地圖*/ void HomeFoodInitial(void); /*食物與家的位置初始化*/ void AntInitial(void); /*螞蟻初始化*/ void WorldChange(void); /*更改環境*/ void AntMove(void); /*螞蟻移動*/ void AntOneStep(void); /*螞蟻動作一步*/ void DealKey(char key); /*按鍵掃描,功能鍵有p,t,1,2,3,s,l*/ void ClearSmellDisp(void); /*關閉信息素的顯示*/ void DispSmell(int type); /*顯示當前信息素的情況*/ int AntNextDir(int xxx,int yyy,int ddir); /*得到螞蟻下一次移動的方向*/ int GetMaxSmell(int type,int xxx,int yyy,int ddir); /*獲取最大信息素的值*/ int IsTrace(int xxx,int yyy); /*是否是曾經走過的路徑*/ int MaxLocation(int num1,int num2,int num3); /*獲得三個值中最大的一個的序號*/ int CanGo(int xxx,int yyy,int ddir); /*返回可以走的路徑*/ int JudgeCanGo(int xxx,int yyy); /*判斷某方向是否可以通過*/ int TurnLeft(int ddir); /*左傳,右轉,后退*/ int TurnRight(int ddir); int TurnBack(int ddir); int MainTimer(void); /*返回自上次調用后經歷了多少個10ms的時間*/ char WaitForKey(int secnum); /*沒有鍵則等待鍵盤輸入,有鍵則返回鍵值*/ void DispPlayTime(void); /*顯示運行時間*/ int TimeUse(void); /*計算時間花費*/ void HideCur(void); /*隱藏鼠標*/ void ResetCur(void); /*重置鼠標*/ /* --------------- */ struct HomeStruct { int xxx,yyy; int amount; /*已經搬運回家的食物數量*/ int TargetFood; /*需要搬運回家的食物數量*/ }home; struct FoodStruct { int xxx,yyy; int amount; /*剩余食物數量*/ }food; struct AntStruct { int xxx,yyy; /*螞蟻當前位置*/ int dir; /*行走方向*/ int speed; /*螞蟻速度,即計數器計到此則移動一步,所以越小螞蟻移動越快*/ int SpeedTimer; /*速度計數器,每10ms記一次*/ int food; /*是否攜帶食物*/ int SmellAmount[2]; /*兩種信息素的含量*/ int tracex[TRACE_REMEMBER]; /*所記憶的x坐標*/ int tracey[TRACE_REMEMBER]; /*所記憶的y坐標*/ int TracePtr; /*記錄路徑所用的指針*/ int IQ; /*好象沒有用到。。。。。*/ }ant[MAX_ANT]; /*全局變量定義*/ int AntNow; /*當前螞蟻*/ int timer10ms; /*記錄多少個10ms已經過去*/ struct time starttime,endtime; /*起始結束時間定義*/ int Smell[2][MAXX+1][MAXY+1]; /*信息素數組*/ int block[MAXX+1][MAXY+1]; /*障礙物數組*/ int SmellGoneTimer; /*信息素消失計數器*/ int SmellDispFlag; /*信息素顯示標志*/ int CanFindFood; /*可以找到獲取食物的路徑標志*/ int HardtoFindPath; /*找到路徑比較困難的標志*/ /* ----- Main -------- */ void main(void) { char KeyPress; int tu; clrscr(); HideCur(); WorldInitial(); do { timer10ms = MainTimer(); if(timer10ms) AntMove(); if(timer10ms) WorldChange(); tu = TimeUse(); if(tu>=60&&!CanFindFood) { gotoxy(1,MAXY+1); printf("Can not find food, maybe a block world."); WaitForKey(10); WorldInitial(); } if(tu>=180&&home.amount<100&&!HardtoFindPath) { gotoxy(1,MAXY+1); printf("God! it is so difficult to find a path."); if(WaitForKey(10)==0x0d) WorldInitial(); else { HardtoFindPath = 1; gotoxy(1,MAXY+1); printf(" "); } } if(home.amount>=home.TargetFood) { gettime(&endtime); KeyPress = WaitForKey(60); DispPlayTime(); WaitForKey(10); WorldInitial(); } else if(kbhit()) { KeyPress = getch(); DealKey(KeyPress); } else KeyPress = NULL; } while(KeyPress!=ESC); gettime(&endtime); DispPlayTime(); WaitForKey(10); clrscr(); ResetCur(); } /* ------ general sub process ----------- */ int MainTimer(void) /* output: how much 10ms have pass from last time call this process */ { static int oldhund,oldsec; struct time t; int timeuse; gettime(&t); timeuse = 0; if(t.ti_hund!=oldhund) { if(t.ti_sec!=oldsec) { timeuse+=100; oldsec = t.ti_sec; } timeuse+=t.ti_hund-oldhund; oldhund = t.ti_hund; } else timeuse = 0; return (timeuse); } char WaitForKey(int secnum) /* funtion: if have key in, exit immediately, else wait 'secnum' senconds then exit input: secnum -- wait this senconds, must < 3600 (1 hour) output: key char, if no key in(exit when timeout), return NULL */ { int secin,secnow; int minin,minnow; int hourin,hournow; int secuse; struct time t; gettime(&t); secin = t.ti_sec; minin = t.ti_min; hourin = t.ti_hour; do { if(kbhit()) return(getch()); gettime(&t); secnow = t.ti_sec; minnow = t.ti_min; hournow = t.ti_hour; if(hournow!=hourin) minnow+=60; if(minnow>minin) secuse = (minnow-1-minin) + (secnow+60-secin); else secuse = secnow - secin; /* counting error check */ if(secuse<0) { gotoxy(1,MAXY+1); printf("Time conuting error, any keyto exit..."); getch(); exit(3); } } while(secuse<=secnum); return (NULL); } void DispPlayTime(void) { int ph,pm,ps; ph = endtime.ti_hour - starttime.ti_hour; pm = endtime.ti_min - starttime.ti_min; ps = endtime.ti_sec - starttime.ti_sec; if(ph<0) ph+=24; if(pm<0) { ph--; pm+=60; } if(ps<0) { pm--; ps+=60; } gotoxy(1,MAXY+1); printf("Time use: %d hour- %d min- %d sec ",ph,pm,ps); } int TimeUse(void) { int ph,pm,ps; gettime(&endtime); ph = endtime.ti_hour - starttime.ti_hour; pm = endtime.ti_min - starttime.ti_min; ps = endtime.ti_sec - starttime.ti_sec; if(ph<0) ph+=24; if(pm<0) { ph--; pm+=60; } if(ps<0) { pm--; ps+=60; } return(ps+(60*(pm+60*ph))); } void HideCur(void) { union REGS regs0; regs0.h.ah=1; regs0.h.ch=0x30; regs0.h.cl=0x31; int86(0x10,®s0,®s0); } void ResetCur(void) { union REGS regs0; regs0.h.ah=1; regs0.h.ch=0x06; regs0.h.cl=0x07; int86(0x10,®s0,®s0); } /* ------------ main ANT programe ------------- */ void WorldInitial(void) { int k,i,j; randomize(); clrscr(); HomeFoodInitial(); for(AntNow=0;AntNow<MAX_ANT;AntNow++) { AntInitial(); } /* of for AntNow */; BlockInitial(); for(k=0;k<=1;k++) /* SMELL TYPE FOOD and HOME */ for(i=0;i<=MAXX;i++) for(j=0;j<=MAXY;j++) Smell[k][i][j] = 0; SmellGoneTimer = 0; gettime(&starttime); SmellDispFlag = 0; CanFindFood = 0; HardtoFindPath = 0; } void BlockInitial(void) { int i,j; int bn; for(i=0;i<=MAXX;i++) for(j=0;j<=MAXY;j++) block[i][j] = 0; bn = 1+ MAX_BLOCK/2 + random(MAX_BLOCK/2); for(i=0;i<=bn;i++) CreatBlock(); } void CreatBlock(void) { int x1,y1,x2,y2; int dx,dy; int i,j; x1 = random(MAXX)+1; y1 = random(MAXY)+1; dx = random(MAXX/10)+1; dy = random(MAXY/10)+1; x2 = x1+dx; y2 = y1+dy; if(x2>MAXX) x2 = MAXX; if(y2>MAXY) y2 = MAXY; if(food.xxx>=x1&&food.xxx<=x2&&food.yyy>=y1&&food.yyy<=y2) return; if(home.xxx>=x1&&home.xxx<=x2&&home.yyy>=y1&&home.yyy<=y2) return; for(i=x1;i<=x2;i++) for(j=y1;j<=y2;j++) { block[i][j] = 1; gotoxy(i,j); putch(BLOCK_CHAR); } } void SaveBlock(void) { FILE *fp_block; char FileNameBlock[20]; int i,j; gotoxy(1,MAXY+1); printf(" "); gotoxy(1,MAXY+1); printf("Save to file...",FileNameBlock); gets(FileNameBlock); if(FileNameBlock[0]==0) strcpy(FileNameBlock,"Ant.ant"); else strcat(FileNameBlock,".ant"); if ((fp_block = fopen(FileNameBlock, "wb")) == NULL) { gotoxy(1,MAXY+1); printf("Creat file %s fail...",FileNameBlock); getch(); exit(2); } gotoxy(1,MAXY+1); printf(" "); fputc(home.xxx,fp_block); fputc(home.yyy,fp_block); fputc(food.xxx,fp_block); fputc(food.yyy,fp_block); for(i=0;i<=MAXX;i++) for(j=0;j<=MAXY;j++) fputc(block[i][j],fp_block); fclose(fp_block); } void LoadBlock(void) { FILE *fp_block; char FileNameBlock[20]; int i,j,k; gotoxy(1,MAXY+1); printf(" "); gotoxy(1,MAXY+1); printf("Load file...",FileNameBlock); gets(FileNameBlock); if(FileNameBlock[0]==0) strcpy(FileNameBlock,"Ant.ant"); else strcat(FileNameBlock,".ant"); if ((fp_block = fopen(FileNameBlock, "rb")) == NULL) { gotoxy(1,MAXY+1); printf("Open file %s fail...",FileNameBlock); getch(); exit(2); } clrscr(); home.xxx = fgetc(fp_block); home.yyy = fgetc(fp_block); food.xxx = fgetc(fp_block); food.yyy = fgetc(fp_block); gotoxy(home.xxx,home.yyy); putch(HOME_CHAR); gotoxy(food.xxx,food.yyy); putch(FOOD_CHAR); food.amount = random(MAX_FOOD/3)+2*MAX_FOOD/3+1; /* food.amount = MAX_FOOD; */ home.amount = 0; home.TargetFood = (food.amount<TARGET_FOOD)?food.amount:TARGET_FOOD; for(AntNow=0;AntNow<MAX_ANT;AntNow++) { AntInitial(); } /* of for AntNow */; for(i=0;i<=MAXX;i++) for(j=0;j<=MAXY;j++) { block[i][j] = fgetc(fp_block); if(block[i][j]) { gotoxy(i,j); putch(BLOCK_CHAR); } } for(k=0;k<=1;k++) /* SMELL TYPE FOOD and HOME */ for(i=0;i<=MAXX;i++) for(j=0;j<=MAXY;j++) Smell[k][i][j] = 0; SmellGoneTimer = 0; gettime(&starttime); SmellDispFlag = 0; CanFindFood = 0; HardtoFindPath = 0; fclose(fp_block); } void HomeFoodInitial(void) { int randnum; int homeplace; /* 1 -- home at left-up, food at right-down -- home at left-down, food at right-up -- home at right-up, food at left-down -- home at right-down, food at left-up */ randnum = random(100); if(randnum<25) homeplace = 1; else if (randnum>=25&&randnum<50) homeplace = 2; else if (randnum>=50&&randnum<75) homeplace = 3; else homeplace = 4; switch(homeplace) { case 1: home.xxx = random(MAXX/3)+1; home.yyy = random(MAXY/3)+1; food.xxx = random(MAXX/3)+2*MAXX/3+1; food.yyy = random(MAXY/3)+2*MAXY/3+1; break; case 2: home.xxx = random(MAXX/3)+1; home.yyy = random(MAXY/3)+2*MAXY/3+1; food.xxx = random(MAXX/3)+2*MAXX/3+1; food.yyy = random(MAXY/3)+1; break; case 3: home.xxx = random(MAXX/3)+2*MAXX/3+1; home.yyy = random(MAXY/3)+1; food.xxx = random(MAXX/3)+1; food.yyy = random(MAXY/3)+2*MAXY/3+1; break; case 4: home.xxx = random(MAXX/3)+2*MAXX/3+1; home.yyy = random(MAXY/3)+2*MAXY/3+1; food.xxx = random(MAXX/3)+1; food.yyy = random(MAXY/3)+1; break; } food.amount = random(MAX_FOOD/3)+2*MAX_FOOD/3+1; /* food.amount = MAX_FOOD; */ home.amount = 0; home.TargetFood = (food.amount<TARGET_FOOD)?food.amount:TARGET_FOOD; /* data correctness check */ if(home.xxx<=0||home.xxx>MAXX||home.yyy<=0||home.yyy>MAXY|| food.xxx<=0||food.xxx>MAXX||food.yyy<=0||food.yyy>MAXY|| food.amount<=0) { gotoxy(1,MAXY+1); printf("World initial fail, any key to exit..."); getch(); exit(2); } gotoxy(home.xxx,home.yyy); putch(HOME_CHAR); gotoxy(food.xxx,food.yyy); putch(FOOD_CHAR); }void AntInitial(void) /* initial ant[AntNow] */ { int randnum; int i; ant[AntNow].xxx = home.xxx; ant[AntNow].yyy = home.yyy; randnum = random(100); if(randnum<25) ant[AntNow].dir = UP; else if (randnum>=25&&randnum<50) ant[AntNow].dir = DOWN; else if (randnum>=50&&randnum<75) ant[AntNow].dir = LEFT; else ant[AntNow].dir = RIGHT; ant[AntNow].speed = 2*(random(INI_SPEED/2)+1); ant[AntNow].SpeedTimer = 0; ant[AntNow].food = 0; ant[AntNow].SmellAmount[SMELL_TYPE_FOOD] = 0; ant[AntNow].SmellAmount[SMELL_TYPE_HOME] = MAX_SMELL; ant[AntNow].IQ = 1; for(i=0;i<TRACE_REMEMBER;i++) { ant[AntNow].tracex[i] = 0; ant[AntNow].tracey[i] = 0; } ant[AntNow].TracePtr = 0; /* a sepecail ant */ if(AntNow==0) ant[AntNow].speed = INI_SPEED; } void WorldChange(void) { int k,i,j; int smelldisp; SmellGoneTimer+=timer10ms; if(SmellGoneTimer>=SMELL_GONE_SPEED) { SmellGoneTimer = 0; for(k=0;k<=1;k++) /* SMELL TYPE FOOD and HOME */ for(i=1;i<=MAXX;i++) for(j=1;j<=MAXY;j++) { if(Smell[k][i][j]) { smelldisp = 1+((10*Smell[k][i][j])/(MAX_SMELL*SMELL_DROP_RATE)); if(smelldisp>=30000||smelldisp<0) smelldisp = 30000; if(SmellDispFlag) { gotoxy(i,j); if((i==food.xxx&&j==food.yyy)||(i==home.xxx&&j==home.yyy)) /* don't over write Food and Home */; else { if(smelldisp>9) putch('#'); else putch(smelldisp+'0'); } } Smell[k][i][j]-= 1+(Smell[k][i][j]*SMELL_GONE_RATE); if(Smell[k][i][j]<0) Smell[k][i][j] = 0; if(SmellDispFlag) { if(Smell[k][i][j]<=2) { gotoxy(i,j); putch(SPACE); } } } } /* of one location */ } /* of time to change the world */ } /* of world change */ void AntMove(void) { int antx,anty; int smelltodrop,smellnow; for(AntNow=0;AntNow<MAX_ANT;AntNow++) { ant[AntNow].SpeedTimer+=timer10ms; if(ant[AntNow].SpeedTimer>=ant[AntNow].speed) { ant[AntNow].SpeedTimer = 0; gotoxy(ant[AntNow].xxx,ant[AntNow].yyy); putch(SPACE); AntOneStep(); gotoxy(ant[AntNow].xxx,ant[AntNow].yyy); /* ant0 is a sepecail ant, use different color */ if(AntNow==0) textcolor(0xd); if(ant[AntNow].food) putch(ANT_CHAR_FOOD); else putch(ANT_CHAR_EMPTY); if(AntNow==0) textcolor(0x7); /* remember trace */ ant[AntNow].tracex[ant[AntNow].TracePtr] = ant[AntNow].xxx; ant[AntNow].tracey[ant[AntNow].TracePtr] = ant[AntNow].yyy; if(++(ant[AntNow].TracePtr)>=TRACE_REMEMBER) ant[AntNow].TracePtr = 0; /* drop smell */ antx = ant[AntNow].xxx; anty = ant[AntNow].yyy; if(ant[AntNow].food) /* have food, looking for home */ { if(ant[AntNow].SmellAmount[SMELL_TYPE_FOOD]) { smellnow = Smell[SMELL_TYPE_FOOD][antx][anty]; smelltodrop = ant[AntNow].SmellAmount[SMELL_TYPE_FOOD]*SMELL_DROP_RATE; if(smelltodrop>smellnow) Smell[SMELL_TYPE_FOOD][antx][anty] = smelltodrop; /* else Smell[...] = smellnow */ ant[AntNow].SmellAmount[SMELL_TYPE_FOOD]-= smelltodrop; if(ant[AntNow].SmellAmount[SMELL_TYPE_FOOD]<0) ant[AntNow].SmellAmount[SMELL_TYPE_FOOD] = 0; } /* of have smell to drop */ } /* of have food */ else /* no food, looking for food */ { if(ant[AntNow].SmellAmount[SMELL_TYPE_HOME]) { smellnow = Smell[SMELL_TYPE_HOME][antx][anty]; smelltodrop = ant[AntNow].SmellAmount[SMELL_TYPE_HOME]*SMELL_DROP_RATE; if(smelltodrop>smellnow) Smell[SMELL_TYPE_HOME][antx][anty] = smelltodrop; /* else Smell[...] = smellnow */ ant[AntNow].SmellAmount[SMELL_TYPE_HOME]-= smelltodrop; if(ant[AntNow].SmellAmount[SMELL_TYPE_HOME]<0) ant[AntNow].SmellAmount[SMELL_TYPE_HOME] = 0; } /* of have smell to drop */ } } /* of time to go */ /* else not go */ } /* of for AntNow */ textcolor(FOOD_HOME_COLOR); gotoxy(home.xxx,home.yyy); putch(HOME_CHAR); gotoxy(food.xxx,food.yyy); if(food.amount>0) putch(FOOD_CHAR); else putch(FOOD_CHAR2); textcolor(7); gotoxy(1,MAXY+1); printf("Food %d, Home %d ",food.amount,home.amount); } void AntOneStep(void) { int ddir,tttx,ttty; int i; ddir = ant[AntNow].dir; tttx = ant[AntNow].xxx; ttty = ant[AntNow].yyy; ddir = AntNextDir(tttx,ttty,ddir); switch(ddir) { case UP: ttty--; break; case DOWN: ttty++; break; case LEFT: tttx--; break; case RIGHT: tttx++; break; default: break; } /* of switch dir */ ant[AntNow].dir = ddir; ant[AntNow].xxx = tttx; ant[AntNow].yyy = ttty; if(ant[AntNow].food) /* this ant carry with food, search for home */ { if(tttx==home.xxx&&ttty==home.yyy) { home.amount++; AntInitial(); } if(tttx==food.xxx&&ttty==food.yyy) ant[AntNow].SmellAmount[SMELL_TYPE_FOOD] = MAX_SMELL; } /* of search for home */ else /* this ant is empty, search for food */ { if(tttx==food.xxx&&ttty==food.yyy) { if(food.amount>0) { ant[AntNow].food = 1; food.amount--; ant[AntNow].SmellAmount[SMELL_TYPE_FOOD] = MAX_SMELL; ant[AntNow].SmellAmount[SMELL_TYPE_HOME] = 0; ant[AntNow].dir = TurnBack(ant[AntNow].dir); for(i=0;i<TRACE_REMEMBER;i++) { ant[AntNow].tracex[i] = 0; ant[AntNow].tracey[i] = 0; } ant[AntNow].TracePtr = 0; CanFindFood = 1; } /* of still have food */ } if(tttx==home.xxx&&ttty==home.yyy) ant[AntNow].SmellAmount[SMELL_TYPE_HOME] = MAX_SMELL; } /* of search for food */ } void DealKey(char key) { int i; switch(key) { case 'p': gettime(&endtime); DispPlayTime(); getch(); gotoxy(1,MAXY+1); for(i=1;i<=MAXX-1;i++) putch(SPACE); break; case 't': if(SmellDispFlag) { SmellDispFlag=0; ClearSmellDisp(); } else SmellDispFlag = 1; break; case '1': DispSmell(SMELL_TYPE_FOOD); getch(); ClearSmellDisp(); break; case '2': DispSmell(SMELL_TYPE_HOME); getch(); ClearSmellDisp(); break; case '3': DispSmell(2); getch(); ClearSmellDisp(); break; case 's': SaveBlock(); break; case 'l': LoadBlock(); break; default: gotoxy(1,MAXY+1); for(i=1;i<=MAXX-1;i++) putch(SPACE); } /* of switch */ } void ClearSmellDisp(void) { int k,i,j; for(k=0;k<=1;k++) /* SMELL TYPE FOOD and HOME */ for(i=1;i<=MAXX;i++) for(j=1;j<=MAXY;j++) { if(Smell[k][i][j]) { gotoxy(i,j); putch(SPACE); } } /* of one location */ } void DispSmell(int type) /* input: 0 -- Only display food smell -- Only display home smell -- Display both food and home smell */ { int k,i,j; int fromk,tok; int smelldisp; switch(type) { case 0: fromk = 0; tok = 0; break; case 1: fromk = 1; tok = 1; break; case 2: fromk = 0; tok = 1; break; default:fromk = 0; tok = 1; break; } SmellGoneTimer = 0; for(k=fromk;k<=tok;k++) /* SMELL TYPE FOOD and HOME */ for(i=1;i<=MAXX;i++) for(j=1;j<=MAXY;j++) { if(Smell[k][i][j]) { smelldisp = 1+((10*Smell[k][i][j])/(MAX_SMELL*SMELL_DROP_RATE)); if(smelldisp>=30000||smelldisp<0) smelldisp = 30000; gotoxy(i,j); if(i!=food.xxx||j!=food.yyy) { if((i==food.xxx&&j==food.yyy)||(i==home.xxx&&j==home.yyy)) /* don't over write Food and Home */; else { if(smelldisp>9) putch('#'); else putch(smelldisp+'0'); } } } } /* of one location */ } int AntNextDir(int xxx,int yyy,int ddir) { int randnum; int testdir; int CanGoState; int cangof,cangol,cangor; int msf,msl,msr,maxms; int type; CanGoState = CanGo(xxx,yyy,ddir); if(CanGoState==0||CanGoState==2||CanGoState==3||CanGoState==6) cangof = 1; else cangof = 0; if(CanGoState==0||CanGoState==1||CanGoState==3||CanGoState==5) cangol = 1; else cangol = 0; if(CanGoState==0||CanGoState==1||CanGoState==2||CanGoState==4) cangor = 1; else cangor = 0; if(ant[AntNow].food) type = SMELL_TYPE_HOME; else type = SMELL_TYPE_FOOD; msf = GetMaxSmell(type,xxx,yyy,ddir); msl = GetMaxSmell(type,xxx,yyy,TurnLeft(ddir)); msr= GetMaxSmell(type,xxx,yyy,TurnRight(ddir)); maxms = MaxLocation(msf,msl,msr); /* maxms - 1 - msf is MAX - msl is MAX - msr is MAX - all 3 number is 0 */ testdir = NULL; switch(maxms) { case 0: /* all is 0, keep testdir = NULL, random select dir */ break; case 1: if(cangof) testdir = ddir; else if(msl>msr) if(cangol) testdir = TurnLeft(ddir); else if(cangor) testdir = TurnRight(ddir); break; case 2: if(cangol) testdir = TurnLeft(ddir); else if(msf>msr) if(cangof) testdir = ddir; else if(cangor) testdir = TurnRight(ddir); break; case 3: if(cangor) testdir = TurnRight(ddir); else if(msf>msl) if(cangof) testdir =ddir; else if(cangol) testdir = TurnLeft(ddir); break; default:break; } /* of maxms */ randnum = random(1000); if(randnum<SMELL_DROP_RATE*1000||testdir==NULL) /* 1. if testdir = NULL, means can not find the max smell or the dir to max smell can not go then random select dir . if ant error, don't follow the smell, random select dir */ { randnum = random(100); switch(CanGoState) { case 0: if(randnum<90) testdir = ddir; else if (randnum>=90&&randnum<95) testdir = TurnLeft(ddir); else testdir = TurnRight(ddir); break; case 1: if(randnum<50) testdir = TurnLeft(ddir); else testdir = TurnRight(ddir); break; case 2: if(randnum<90) testdir = ddir; else testdir = TurnRight(ddir); break; case 3: if(randnum<90) testdir = ddir; else testdir = TurnLeft(ddir); break; case 4: testdir = TurnRight(ddir); break; case 5: testdir = TurnLeft(ddir); break; case 6: testdir = ddir; break; case 7: testdir = TurnBack(ddir); break; default:testdir = TurnBack(ddir); } /* of can go state */ } return(testdir); } int GetMaxSmell(int type,int xxx,int yyy,int ddir) { int i,j; int ms; /* MAX smell */ ms = 0; switch(ddir) { case UP: for(i=xxx-ANT_EYESHOT;i<=xxx+ANT_EYESHOT;i++) for(j=yyy-ANT_EYESHOT;j<yyy;j++) { if(!JudgeCanGo(i,j)) continue; if((i==food.xxx&&j==food.yyy&&type==SMELL_TYPE_FOOD)|| (i==home.xxx&&j==home.yyy&&type==SMELL_TYPE_HOME)) { ms = MAX_SMELL; break; } if(IsTrace(i,j)) continue; if(Smell[type][i][j]>ms) ms = Smell[type][i][j]; } break; case DOWN: for(i=xxx-ANT_EYESHOT;i<=xxx+ANT_EYESHOT;i++) for(j=yyy+1;j<=yyy+ANT_EYESHOT;j++) { if(!JudgeCanGo(i,j)) continue; if((i==food.xxx&&j==food.yyy&&type==SMELL_TYPE_FOOD)|| (i==home.xxx&&j==home.yyy&&type==SMELL_TYPE_HOME)) { ms = MAX_SMELL; break; } if(IsTrace(i,j)) continue; if(Smell[type][i][j]>ms) ms = Smell[type][i][j]; } break; case LEFT: for(i=xxx-ANT_EYESHOT;i<xxx;i++) for(j=yyy-ANT_EYESHOT;j<=yyy+ANT_EYESHOT;j++) { if(!JudgeCanGo(i,j)) continue; if((i==food.xxx&&j==food.yyy&&type==SMELL_TYPE_FOOD)|| (i==home.xxx&&j==home.yyy&&type==SMELL_TYPE_HOME)) { ms = MAX_SMELL; break; } if(IsTrace(i,j)) continue; if(Smell[type][i][j]>ms) ms = Smell[type][i][j]; } break; case RIGHT: for(i=xxx+1;i<=xxx+ANT_EYESHOT;i++) for(j=yyy-ANT_EYESHOT;j<=yyy+ANT_EYESHOT;j++) { if(!JudgeCanGo(i,j)) continue; if((i==food.xxx&&j==food.yyy&&type==SMELL_TYPE_FOOD)|| (i==home.xxx&&j==home.yyy&&type==SMELL_TYPE_HOME)) { ms = MAX_SMELL; break; } if(IsTrace(i,j)) continue; if(Smell[type][i][j]>ms) ms = Smell[type][i][j]; } break; default: break; } return(ms); } int IsTrace(int xxx,int yyy) { int i; for(i=0;i<TRACE_REMEMBER;i++) if(ant[AntNow].tracex[i]==xxx&&ant[AntNow].tracey[i]==yyy) return(1); return(0); } int MaxLocation(int num1,int num2,int num3) { int maxnum; if(num1==0&&num2==0&&num3==0) return(0); maxnum = num1; if(num2>maxnum) maxnum = num2; if(num3>maxnum) maxnum = num3; if(maxnum==num1) return(1); if(maxnum==num2) return(2); if(maxnum==num3) return(3); } int CanGo(int xxx,int yyy,int ddir) /* input: xxx,yyy - location of ant ddir - now dir output: 0 - forward and left and right can go - forward can not go - left can not go - right can not go - forward and left can not go - forward and right can not go - left and right can not go - forward and left and right all can not go */ { int tx,ty,tdir; int okf,okl,okr; /* forward can go ? */ tdir = ddir; tx = xxx; ty = yyy; switch(tdir) { case UP: ty--; break; case DOWN: ty++; break; case LEFT: tx--; break; case RIGHT: tx++; break; default: break; } /* of switch dir */ if(JudgeCanGo(tx,ty)) okf = 1; else okf = 0; /* turn left can go ? */ tdir = TurnLeft(ddir); tx = xxx; ty = yyy; switch(tdir) { case UP: ty--; break; case DOWN: ty++; break; case LEFT: tx--; break; case RIGHT: tx++; break; default: break; } /* of switch dir */ if(JudgeCanGo(tx,ty)) okl = 1; else okl = 0; /* turn right can go ? */ tdir = TurnRight(ddir); tx = xxx; ty = yyy; switch(tdir) { case UP: ty--; break; case DOWN: ty++; break; case LEFT: tx--; break; case RIGHT: tx++; break; default: break; } /* of switch dir */ if(JudgeCanGo(tx,ty)) okr = 1; else okr = 0; if(okf&&okl&&okr) return(0); if(!okf&&okl&&okr) return(1); if(okf&&!okl&&okr) return(2); if(okf&&okl&&!okr) return(3); if(!okf&&!okl&&okr) return(4); if(!okf&&okl&&!okr) return(5); if(okf&&!okl&&!okr) return(6); if(!okf&&!okl&&!okr) return(7); return(7); } int JudgeCanGo(int xxx,int yyy) /* input: location to judeg output: 0 -- can not go -- can go */ { int i,j; if(xxx<=0||xxx>MAXX) return(0); if(yyy<=0||yyy>MAXY) return(0); if(block[xxx][yyy]) return(0); return(1); } int TurnLeft(int ddir) { switch(ddir) { case UP: return(LEFT); case DOWN: return(RIGHT); case LEFT: return(DOWN); case RIGHT: return(UP); default: break; } /* of switch dir */ } int TurnRight(int ddir) { switch(ddir) { case UP: return(RIGHT); case DOWN: return(LEFT); case LEFT: return(UP); case RIGHT: return(DOWN); default: break; } /* of switch dir */ } int TurnBack(int ddir) { switch(ddir) { case UP: return(DOWN); case DOWN: return(UP); case LEFT: return(RIGHT); case RIGHT: return(LEFT); default: break; } /* of switch dir */ }