README.md

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

Solutions (Rust)

1. Prefix Sum

impl Solution {
    pub fn xor_queries(arr: Vec<i32>, queries: Vec<Vec<i32>>) -> Vec<i32> {
        let mut arr = arr;
        let mut ret = Vec::new();

        for i in 1..arr.len() {
            arr[i] ^= arr[i - 1];
        }

        for query in queries {
            let l = query[0] as usize;
            let r = query[1] as usize;
            ret.push(arr.get(l - 1).unwrap_or(&0) ^ arr[r]);
        }

        ret
    }
}