合并两个已排序的序列（merge）——Python实现

# 合并两个已排序的序列 merge

# 输入：已排序的数组A1、A2

# 输出：合并且排好序的数组B

 

 1 def merge(A1,A2):
 2 
 3     a1 = 0                          # 指向数组A1的指针
 4     a2 = 0                          # 指向数组A2的指针
 5     n1 = len(A1)-1                  # 数组A1的最大下标
 6     n2 = len(A2)-1                  # 数组A2的最大下标
 7     B = [ 0 for i in range(n1+n2+1)]          # 数组B用于存放合并结果，长度为数组A1，A2的长度之和
 8     b = 0                           # 指向数组B 的指针
 9 
10     while a1<=n1 and a2<=n2:
11         if A1[a1] <= A2[a2]:
12             B[b] = A1[a1]
13             b = b+1
14             a1 = a1+1
15         else:                       # A1[a1] > A2[a2]
16             B[b] = A2[a2]
17             b = b+1
18             a2 = a2+1
19         print(B)                    # 打印填充数组B的过程
20     return B

函数调用

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

运行结果

[-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]

合并结果为：
[-88, -34, -22, -20, -11, -2, 2, 9, 20, 29, 30, 30, 66, 78, 129]