DDSA Solutions

3192. Minimum Operations to Make Binary Array Elements Equal to One II

EasyView on LeetCode
ArrayDynamic ProgrammingGreedy
Time: O(n)
Space: O(1)

Problem Overview

Minimum operations to alternate binary array.

Intuition

Minimum operations to alternate binary array. Compare with patterns 010101... and 101010..., return min mismatches.

Algorithm

  1. 1Count mismatches with pattern starting with 0. Answer = min(mismatches, n - mismatches).

Common Pitfalls

  • •Two valid alternating patterns. Count mismatches with one, n-count for the other. Return min.
3192.cs
C#
// Approach: Greedy; count flips needed tracking current parity.
// Time: O(n) Space: O(1)

public class Solution {
    public int MinOperations(int[] nums) {
        int n = nums.Length, ans = 0, times = 0;

        for(int i = 0; i < n; i++)
        {
            if((nums[i] == 1 && times % 2 == 1) || (nums[i] == 0 && times % 2 == 0))
                times++;
        }
        return times;
    }
}
Was this solution helpful?

Related Problems