exclusive_or.cpp

#pragma optimize("O3")

#include <bits/stdc++.h>
using namespace std;

#define all(x) begin(x), end(x)
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<ll> vll;
typedef vector<vll> vvll;
typedef vector<bool> vb;
typedef vector<vb> vvb;

struct DSU {
    vi parent, size;

    void init_dsu(int n) {
        parent = vi(n);
        size = vi(n, 1);
        for (int i = 0; i < n; i++) {
            parent[i] = i;
        }
    }

    int find_set(int v) {
        if (v == parent[v])
            return v;
        return parent[v] = find_set(parent[v]);
    }

    void union_sets(int a, int b) {
        a = find_set(a);
        b = find_set(b);
        if (a == b)
            return;
        if (size[a] < size[b])
            swap(a, b);
        parent[b] = a;
        size[a] += size[b];
    }
};

struct edge {
    int a, b, x;
};

int main() {
    cin.tie(0)->sync_with_stdio(0);
    int n, m;
    cin >> n >> m;

    DSU dsu;
    vector<edge> zero_edges;
    vector<edge> one_edges;
    while (m--) {
        char tchar;
        string tstring;
        int a, b, c;
        cin >> tchar >> a >> tstring >> tchar >> b >> tstring >> c;
        if (c == 0)
            zero_edges.push_back({a, b, c});
        if (c == 1)
            one_edges.push_back({a, b, c});
    }

    dsu.init_dsu(n + 1);
    for (edge e : zero_edges) {
        dsu.union_sets(e.a, e.b);
    }

    for (edge e : one_edges) {
        if (dsu.find_set(e.a) == dsu.find_set(e.b)) {
            cout << "NO" << endl;
            return 0;
        }
    }

    cout << "YES" << endl;

}