LeetCode 238. 除自身以外数组的乘积

题目链接：

力扣[这里是图片001]https://leetcode-cn.com/problems/product-of-array-except-self/

【分析】算出当前元素的前缀乘 和 后缀乘即可。

class Solution {
    public int[] productExceptSelf(int[] nums) {
        int n = nums.length;
        int i;
        int[] l = new int[n + 1]; l[0] = 1;
        int[] r = new int[n + 1]; r[n] = 1;
        for(i = 0; i < n; i++){
            l[i + 1] = l[i] * nums[i];
        }
        for(i = n - 1; i >= 0; i--){
            r[i] = r[i + 1] * nums[i];
        }
        int[] ans = new int[n];
        for(i = 0; i < n; i++){
            ans[i] = l[i] * r[i + 1];
        }
        return ans;
    }
}