1720. Decode XORed Array
There is a hidden integer array arr
that consists of n
non-negative integers.
It was encoded into another integer array encoded
of length n - 1
, such that encoded[i] = arr[i] XOR arr[i + 1]
. For example, if arr = [1,0,2,1]
, then encoded = [1,2,3]
.
You are given the encoded
array. You are also given an integer first
, that is the first element of arr
, i.e. arr[0]
.
Return the original array arr
. It can be proved that the answer exists and is unique.
Example 1:
Input: encoded = [1,2,3], first = 1 Output: [1,0,2,1] Explanation: If arr = [1,0,2,1], then first = 1 and encoded = [1 XOR 0, 0 XOR 2, 2 XOR 1] = [1,2,3]
Example 2:
Input: encoded = [6,2,7,3], first = 4 Output: [4,2,0,7,4]
Constraints:
2 <= n <= 104
encoded.length == n - 1
0 <= encoded[i] <= 105
0 <= first <= 105
Rust Solution
struct Solution;
impl Solution {
fn decode(encoded: Vec<i32>, first: i32) -> Vec<i32> {
let n = encoded.len();
let mut res = vec![];
res.push(first);
for i in 0..n {
res.push(res[i] ^ encoded[i]);
}
res
}
}
#[test]
fn test() {
let encoded = vec![1, 2, 3];
let first = 1;
let res = vec![1, 0, 2, 1];
assert_eq!(Solution::decode(encoded, first), res);
let encoded = vec![6, 2, 7, 3];
let first = 4;
let res = vec![4, 2, 0, 7, 4];
assert_eq!(Solution::decode(encoded, first), res);
}
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