Untitled

#include <iostream>
#include <vector>
using namespace std;

int maxEvenSumPairs(vector<int> &A) {
    int n = A.size();
    vector<bool> paired(n, false); // Track whether an element is already paired
    int count = 0;

    for (int i = 0; i < n; i++) {
        int next = (i + 1) % n; // Circular indexing

        if (!paired[i] && !paired[next] && (A[i] + A[next]) % 2 == 0) {
            paired[i] = paired[next] = true;
            count++;
        }
    }

    return count;
}

int main() {
    vector<vector<int>> testCases = {
        {4, 2, 5, 8, 7, 3, 7}, // Expected output: 2
        {1, 3, 5, 7},          // Expected output: 2
        {2, 4, 6, 8},          // Expected output: 2
        {1, 2, 3, 4, 5, 6},    // Expected output: 0
        {10, 20, 30, 40, 50}   // Expected output: 2
    };

    for (int i = 0; i < testCases.size(); i++) {
        cout << "Test Case " << i + 1 << ": ";
        cout << maxEvenSumPairs(testCases[i]) << endl;
    }

    return 0;
}