leetcode 1588. 所有奇数长度子数组的和-耗时100-Sum of All Odd Length Subarrays

Problem: leetcode 1588. 所有奇数长度子数组的和-耗时100-Sum of All Odd Length Subarrays耗时100%算出前缀和然后对长度是奇数的子数组累加求和的Codeclass Solution { public: int sumOddLengthSubarrays(vectorint arr) { vectorint prefix{0}; for(int i : arr) prefix.push_back(prefix.back() i); int n arr.size(), sum 0; for(int i 0; i n; i) { for(int j i 1; j n; j) { if(((j-i)1)1) sum prefix[j] - prefix[i]; } } return sum; } };