LeetCode剑指 Offer 66. 构建乘积数组

//剑指 Offer 66. 构建乘积数组 //维护两个数组：l,r //l[i]：原数组左边所有元素的乘积 //r[i]：原数组右边所有元素的乘积 //这样，ans[i]就等于l[i] * r[i] class Solution { public: vector<int> constructArr(vector<int>& a) { int n = a.size(); vector<int>l(n, 1); vector<int>r(n, 1); for (int i = 1; i < n; i++) { l[i] = l[i - 1] * a[i - 1]; r[n - 1 - i] = r[n - i] * a[n - i]; } auto ans = a; for (int i = 0; i < n; i++) ans[i] = l[i] * r[i]; return ans; } };