LeetCode-in-Java

3936. Minimum Swaps to Move Zeros to End

Easy

You are given an integer array nums.

In one operation, you can choose any two distinct indices i and j and swap nums[i] and nums[j].

Return an integer denoting the minimum number of operations required to move all 0s to the end of the array.

Example 1:

Input: nums = [0,1,0,3,12]

Output: 2

Explanation:

We perform the following swap operations:

• Swap nums[0] and nums[3], giving nums = [3, 1, 0, 0, 12].
• Swap nums[2] and nums[4], giving nums = [3, 1, 12, 0, 0].

Thus, the answer is 2.

Example 2:

Input: nums = [0,1,0,2]

Output: 1

Explanation:

We perform the following swap operations:

• Swap nums[0] and nums[3], giving nums = [2, 1, 0, 0].

Thus, the answer is 1.

Example 3:

Input: nums = [1,2,0]

Output: 0

Explanation:

The array already satisfies the condition. Therefore, no swap operations are needed.

Constraints:

• 1 <= nums.length <= 100
• 0 <= nums[i] <= 100

Solution

public class Solution {
    private void swap(int[] nums, int i, int j) {
        int temp = nums[i];
        nums[i] = nums[j];
        nums[j] = temp;
    }

    public int minimumSwaps(int[] nums) {
        int n = nums.length;
        int count = 0;
        int l = 0;
        int r = n - 1;
        while (l < r) {
            if (nums[l] == 0 && nums[r] != 0) {
                swap(nums, l, r);
                count++;
                l++;
                r--;
            } else if (nums[l] != 0) {
                l++;
            } else if (nums[r] == 0) {
                r--;
            }
        }
        return count;
    }
}

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