Product of Array Except Self

Given an array of n integers where n > 1, nums, return an array output such that output[i] is equal to the product of all the elements of nums except nums[i].

Solve it without division and in O(n).

For example, given [1,2,3,4], return [24,12,8,6].

Follow up:
Could you solve it with constant space complexity? (Note: The output array does not count as extra space for the purpose of space complexity analysis.)

class Solution {
public:
    vector<int> productExceptSelf(vector<int>& nums) {
        int numsSize = nums.size();
        vector<int> res(numsSize,1);
        for(int i=1;i<numsSize;i++){
            res[i] = nums[i-1]*res[i-1];
        }
        int tmp  = 1;
        for(int i=numsSize-1;i>=0;i--){
            res[i] = res[i]*tmp;
            tmp *= nums[i];
        }
        return res;
    }
};

Product of Array Except Self

原文：http://www.cnblogs.com/zengzy/p/5003043.html