bipartite.cpp

#include <iostream>
#include <vector>
#include <queue>

using std::queue;
using std::vector;

bool bipartite(vector<vector<int>>& adj) {
	int n = adj.size();
	vector<int> side(n, -1);
	bool is_bipartite = true;
	queue<int> q;
	for (int st = 0; st < n; ++st) {
		if (side[st] == -1) {
			q.push(st);
			side[st] = 0;
			while (!q.empty()) {
				int v = q.front();
				q.pop();
				for (int u : adj[v]) {
					if (side[u] == -1) {
						side[u] = side[v] ^ 1;
						q.push(u);
					} else {
						is_bipartite &= side[u] != side[v];
					}
				}
			}
		}
	}

	return is_bipartite;
}

int main() {
	int n, m;
	std::cin >> n >> m;
	vector<vector<int>> adj(n, vector<int>());
	for (int i = 0; i < m; i++) {
		int x, y;
		std::cin >> x >> y;
		adj[x - 1].push_back(y - 1);
		adj[y - 1].push_back(x - 1);
	}
	std::cout << (bipartite(adj) ? 1 : 0);
}