[LeetCode]303. Range Sum Query

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. You may assume that the array does not change.
2. There are many calls to sumRange function.

类型：Dynamic Programming

public class NumArray {    private int[] sums;    public NumArray(int[] nums) {        sums = new int[nums.length+1];        for(int i=1; i<nums.length+1; i++)            sums[i]=nums[i-1]+sums[i-1];    }        public int sumRange(int i, int j) {                return sums[j+1]-sums[i];    }}/** * Your NumArray object will be instantiated and called as such: * NumArray obj = new NumArray(nums); * int param_1 = obj.sumRange(i,j); */

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