1310. XOR Queries of a Subarray

Given the array arr of positive integers and the array queries where queries[i] = [Li, Ri], for each query i compute the XOR of elements from Li to Ri (that is, arr[Li] xor arr[Li+1] xor ... xor arr[Ri] ). Return an array containing the result for the given queries.

 

Example 1:

Input: arr = [1,3,4,8], queries = [[0,1],[1,2],[0,3],[3,3]]
Output: [2,7,14,8] 
Explanation: 
The binary representation of the elements in the array are:
1 = 0001 
3 = 0011 
4 = 0100 
8 = 1000 
The XOR values for queries are:
[0,1] = 1 xor 3 = 2 
[1,2] = 3 xor 4 = 7 
[0,3] = 1 xor 3 xor 4 xor 8 = 14 
[3,3] = 8

Example 2:

Input: arr = [4,8,2,10], queries = [[2,3],[1,3],[0,0],[0,3]]
Output: [8,0,4,4]

 

Constraints:

  • 1 <= arr.length <= 3 * 10^4
  • 1 <= arr[i] <= 10^9
  • 1 <= queries.length <= 3 * 10^4
  • queries[i].length == 2
  • 0 <= queries[i][0] <= queries[i][1] < arr.length

Rust Solution

struct Solution;

impl Solution {
    fn xor_queries(mut arr: Vec<i32>, queries: Vec<Vec<i32>>) -> Vec<i32> {
        let n = arr.len();
        for i in 1..n {
            arr[i] ^= arr[i - 1];
        }
        let mut res = vec![];
        for query in queries {
            let l = query[0] as usize;
            let r = query[1] as usize;
            let x = if l > 0 { arr[r] ^ arr[l - 1] } else { arr[r] };
            res.push(x);
        }
        res
    }
}

#[test]
fn test() {
    let arr = vec![1, 3, 4, 8];
    let queries = vec_vec_i32![[0, 1], [1, 2], [0, 3], [3, 3]];
    let res = vec![2, 7, 14, 8];
    assert_eq!(Solution::xor_queries(arr, queries), res);
    let arr = vec![4, 8, 2, 10];
    let queries = vec_vec_i32![[2, 3], [1, 3], [0, 0], [0, 3]];
    let res = vec![8, 0, 4, 4];
    assert_eq!(Solution::xor_queries(arr, queries), res);
}

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