(java)Range Sum Query - Immutable

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) -> 1
sumRange(2, 5) -> -1
sumRange(0, 5) -> -3

Note:

You may assume that the array does not change.

There are many calls to sumRange function.

// Your NumArray object will be instantiated and called as such:

// NumArray numArray = new NumArray(nums);

// numArray.sumRange(0, 1);

// numArray.sumRange(1, 2);

思路:根据他的调用，无非就是添加一个钩子方法
代人如下(已通过leetcode)
public class NumArray {

private int[]nums;

public NumArray(int[] nums) {

this.nums=nums;

}

public int sumRange(int i, int j) {

int sum=0;

for(int k=i;k<=j;k++) {

sum+=nums[k];

}

return sum;

}

}