2134. Minimum Swaps to Group All 1's Together II.cpp

class Solution {
public:
    int minSwaps(vector<int>& nums) {
    
        int op1 = minSwapsHelper(nums, 0);  
        int op2 = minSwapsHelper(nums, 1);  
        return min(op1, op2);
    }

    int minSwapsHelper(vector<int>& data, int val) {
        int length = data.size();
        int totalValCount = 0;

        for (int i = length - 1; i >= 0; i--) {
            if (data[i] == val) totalValCount++;
        }

        if (totalValCount == 0 || totalValCount == length) return 0;

        int start = 0, end = 0;
        int maxValInWindow = 0, currentValInWindow = 0;
        
        while (end < totalValCount) {
            if (data[end++] == val) currentValInWindow++;
        }
        maxValInWindow = max(maxValInWindow, currentValInWindow);

        while (end < length) {
            if (data[start++] == val) currentValInWindow--;
            if (data[end++] == val) currentValInWindow++;
            maxValInWindow = max(maxValInWindow, currentValInWindow);
        }

        return totalValCount - maxValInWindow;
    }
};