<!doctype html> <head> <meta charset = "utf-8" /> </head> <body> <script> /** 循環移動數組 => ab轉換為ba => (a逆置b逆置)逆置 = ba @arr 移動的數組 @count 移動多少位 正數表示左移，負數表示右移 */ const recycMoveArray = function(arr,count){ let end = arr.length - 1; //獲取數組的結束下標 /* //左移 reverse(0, count-1); //a逆置 reverse(count, end); //b逆置 reverse(0, end); //整體逆置 //右移 reverse(0, end + count); //實際上可以轉成左移情況 reverse(end + count + 1, end); reverse(0, end); */ /* let leftArrEnd = 0; //a數組的結束下標 //判斷左移還是右移 if(count > 0){ leftArrEnd = count - 1; }else{ leftArrEnd = end + count; } */ let leftArrEnd = count > 0 ? --count : end + count; reverse(arr,0,leftArrEnd); reverse(arr,leftArrEnd+1,end); reverse(arr,0,end); } /** 將數組逆置的函數 @param arr 逆置的數組 @param start 逆置數組的開始下標 @param end 逆置數組的結束下標 */ const reverse = function(arr,start,end){ //如果指針不等 while(start <= end){ //start != end是有缺陷的，當是偶數個時不能跳出 //調換start和end指向的值 let temp = arr[start]; arr[start] = arr[end]; arr[end] = temp; //指針移動 start++; end--; } } let arr = new Array("a","b","c","d","e","f","g","h"); recycMoveArray(arr,3); document.write(arr); //defghabc </script> </body> </html>