Leetcode 303. Range Sum query-immutable (prefix and)

Given an integer array nums, find the sum of the elements between indices I and J (i ≤ J), inclusive.

Example:

Given nums = [-2, 0, 3, -5, 2, -1]sumrange (0, 2), 1sumRange (2, 5), -1sumrange (0, 5), 3

Note:

1. Assume that the array does is not a change.
2. There is many calls to sumrange function.

Prefix and the application, very simple.

classNumarray { Public:    intN; Vector<int>s; Numarray (Vector<int> &nums) {N=nums.size (); if(n==0)return; S.push_back (nums[0]);  for(intI=1; i<n;i++) {S.push_back (S.back ()+Nums[i]); }    }    intSumrange (intIintj) {if(I&GT;J)return 0; if(i==0)returnS[j]; returns[j]-s[i-1]; }};//Your Numarray object would be instantiated and called as such://Numarray Numarray (nums);//numarray.sumrange (0, 1);//Numarray.sumrange (1, 2);

Leetcode 303. Range Sum query-immutable (prefix and)