Replace elements in an array

Array Hash Table Simulation

59.6% acceptance

Feb 25, 2026

680

You are given a 0-indexed array nums that consists of n distinct positive integers. Apply m operations to this array, where in the ith operation you replace the number operations[i][0] with operations[i][1]. It is guaranteed that in the ith operation: operations[i][0] exists in nums. operations[i][1] does not exist in nums. Return the array obtained after applying all the operations.

Solution

Rust

Time O(n)

Space O(n)

LeetCode

solution.rs

use std::collections::HashMap;


impl Solution {
  pub fn array_change(mut nums: Vec<i32>, operations: Vec<Vec<i32>>) -> Vec<i32> {
    let mut index_map: HashMap<i32, usize> = HashMap::new();
    for (i, &v) in nums.iter().enumerate() {
      index_map.insert(v, i);
    }
    for op in &operations {
      let (from, to) = (op[0], op[1]);
      let idx = index_map.remove(&from).unwrap();
      nums[idx] = to;
      index_map.insert(to, idx);
    }
    nums
  }
}