SDA - test 6 - 2020-2021 - Премахване на ребра

#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
#include <unordered_map>

using namespace std;

unordered_map<int, vector<int>> graph;
vector<bool> visited(100, false);
int children[100]{ 0 };

int countChildren(int a) {
    visited[a] = true;
    if (graph[a].empty()) {
        return 0;
    }

    for (int child : graph[a]) {
        if(!visited[child])
            children[a] += countChildren(child) + 1;
    }
    return children[a];
}

int main() {
    int v, e, a, b;
    cin >> v >> e;
    for (int i = 0; i < e; i++) {
        cin >> a >> b;
        graph[a].push_back(b);
        graph[b].push_back(a);
    }
    countChildren(1);
    int count = 0;
    for (int i = 0; i < v; i++) {
        if (children[i] % 2 == 1)
            count++;
    }
    cout << count - 1;
    return 0;
}