875836. Two Swaps
Easy
Two Swaps
Summary
The Two Swaps problem involves given an array of integers and a target sum. The goal is to find two elements in the array that add up to the target sum by performing at most two swaps.
Detailed Explanation
To solve this problem, we can start by sorting the array in ascending order. This will ensure that adjacent elements are either equal or have a difference of 1. Then, we iterate through the sorted array and check for pairs of elements that add up to the target sum. If such a pair is found, we return their indices as the solution.
Here's a step-by-step breakdown:
- Sort the given array in ascending order.
- Initialize two pointers,
iandj, to the start and end of the array respectively. - Iterate through the array until
imeets or crossesj. - Check if the sum of the elements at indices
iandjequals the target sum. - If a pair is found that adds up to the target sum, return their indices as the solution.
Time Complexity: O(n log n) due to sorting Space Complexity: O(1) since we only use a constant amount of space
Optimized Solutions
Java
public class TwoSwaps {
public static int[] findTwoSwaps(int[] arr, int targetSum) {
Arrays.sort(arr);
int i = 0;
int j = arr.length - 1;
while (i < j) {
int sum = arr[i] + arr[j];
if (sum == targetSum) {
return new int[]{i, j};
} else if (sum < targetSum) {
i++;
} else {
j--;
}
}
return null;
}
}