合並兩個已排序的序列（merge）——Python實現

# 合並兩個已排序的序列 merge

# 輸入：已排序的數組A1、A2

# 輸出：合並且排好序的數組B

 

def merge(A1,A2):

    a1 = 0                          # 指向數組A1的指針
    a2 = 0                          # 指向數組A2的指針
    n1 = len(A1)-1                  # 數組A1的最大下標
    n2 = len(A2)-1                  # 數組A2的最大下標
    B = [ 0 for i in range(n1+n2+1)]          # 數組B用於存放合並結果，長度為數組A1，A2的長度之和
    b = 0                           # 指向數組B 的指針

    while a1<=n1 and a2<=n2:
        if A1[a1] <= A2[a2]:
            B[b] = A1[a1]
            b = b+1
            a1 = a1+1
        else:                       # A1[a1] > A2[a2]
            B[b] = A2[a2]
            b = b+1
            a2 = a2+1
        print(B)                    # 打印填充數組B的過程
    return B

 

函數調用

A1 = [-34,-22,-11,2,9,20,30,78,243]
A2 = [-88,-20,-2,29,30,66,129]
print(merge(A1,A2))

 

運行結果

[-88, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[-88, -34, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[-88, -34, -22, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[-88, -34, -22, -20, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[-88, -34, -22, -20, -11, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[-88, -34, -22, -20, -11, -2, 0, 0, 0, 0, 0, 0, 0, 0, 0]
[-88, -34, -22, -20, -11, -2, 2, 0, 0, 0, 0, 0, 0, 0, 0]
[-88, -34, -22, -20, -11, -2, 2, 9, 0, 0, 0, 0, 0, 0, 0]
[-88, -34, -22, -20, -11, -2, 2, 9, 20, 0, 0, 0, 0, 0, 0]
[-88, -34, -22, -20, -11, -2, 2, 9, 20, 29, 0, 0, 0, 0, 0]
[-88, -34, -22, -20, -11, -2, 2, 9, 20, 29, 30, 0, 0, 0, 0]
[-88, -34, -22, -20, -11, -2, 2, 9, 20, 29, 30, 30, 0, 0, 0]
[-88, -34, -22, -20, -11, -2, 2, 9, 20, 29, 30, 30, 66, 0, 0]
[-88, -34, -22, -20, -11, -2, 2, 9, 20, 29, 30, 30, 66, 78, 0]
[-88, -34, -22, -20, -11, -2, 2, 9, 20, 29, 30, 30, 66, 78, 129]

合並結果為：
[-88, -34, -22, -20, -11, -2, 2, 9, 20, 29, 30, 30, 66, 78, 129]