XOR Queries of a Subarray

给一个数组和一个queries数组, 让返回一个数组, 是queries中范围的xor值. 这个题就是pre sum.

class Solution {
    public int[] xorQueries(int[] arr, int[][] queries) {
        for(int i = 1; i < arr.length; i++) {
            arr[i] = arr[i] ^ arr[i-1];
        }
        int[] res = new int[queries.length];
        for(int i = 0; i < queries.length; i++) {
            if(queries[i][0] > 0)
                res[i] = arr[queries[i][1]] ^ arr[queries[i][0]-1];
            else
                res[i] = arr[queries[i][1]];
        }
        return res;
    }
}