构建乘积数组
题目描述
给定一个数组A[0,1,...,n-1],请构建一个数组B[0,1,...,n-1],其中B中的元素B[i]=A[0]A[1]...A[i-1]A[i+1]...A[n-1]。不能使用除法。
python solution:
# -*- coding:utf-8 -*-
class Solution:
def multiply(self, A):
length = len(A)
B = [0 for i in range(length)]
if length!=0:
B[0] = 1
#计算下三角的结果
for i in range(1,length):
B[i] = B[i-1]*A[i-1]
temp = 1
#计算上三角的结果
for j in range(length-2,-1,-1):
temp *= A[j+1]
B[j] *= temp
return B