lab11(2).cpp

#include <bits/stdc++.h>
typedef long long int lli;
typedef unsigned long long int ulli;
typedef long double ldb;

#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;

#define pb push_back
#define popb pop_back()
#define pf push_front
#define popf pop_front()
#define si size()
#define be begin()
#define en end()
#define all(v) v.be, v.en
#define le length()
#define mp make_pair
#define mt make_tuple
#define acc(v) accumulate(all(v), 0)
#define F first
#define S second

#define forz(i, n) for (int i = 0; i < n; i++)
#define fore(i, m, n) for (int i = m; i <= n; i++)
#define rforz(i, n) for (int i = n - 1; i >= 0; i--)
#define rforzm(i, m, n) for (int i = n - 1; i >= m; i--)
#define deci(n) fixed << setprecision(n)
#define high(n) __builtin_popcount(n)
#define highll(n) __builtin_popcountll(n)
#define parity(n) __builtin_parity(n)
#define ctz(n) __builtin_ctz(n)
#define lb lower_bound
#define ub upper_bound
#define er equal_range
#define maxe *max_element
#define mine *min_element
#define mod 1000000007
#define mod2 998244353
#define gcd __gcd
#define kira ios::sync_with_stdio(0), cin.tie(0), cout.tie(0)

#define endl "\n"
#define p0(a) cout << a << " "
#define p1(a) cout << a << endl
#define p2(a, b) cout << a << " " << b << endl
#define p3(a, b, c) cout << a << " " << b << " " << c << endl
#define p4(a, b, c, d) cout << a << " " << b << " " << c << " " << d << endl

#define oset tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update>
#define osetlli tree<lli, null_type, less<lli>, rb_tree_tag, tree_order_statistics_node_update>
//member functions :
//1. order_of_key(k) : number of elements strictly lesser than k
//2. find_by_order(k) : k-th element in the set
#define ofk order_of_key
#define fbo find_by_order
using namespace std;

/*STD fucntions*/
lli power(lli x, lli y, lli p)
{
    lli res = 1;
    x = x % p;
    while (y > 0)
    {
        if (y & 1)
            res = (res * x) % p;
        //y must be even now
        y = y >> 1; //y=y/2
        x = (x * x) % p;
    }
    return res;
}
lli modi(lli a, lli m)
{
    // fermat little thm where m is prime
    return power(a, m - 2, m);
}
/*CODE BEGINS*/
const int N = 4e6 + 10;
vector<lli> adj[N];
vector<lli> color(N, -1);
int main()
{
    kira;
    lli n, m, u, v, w;
    cin >> n >> m;
    forz(i, m)
    {
        cin >> u >> v >> w;
        if (w % 2 == 0)
        {
            n++;
            adj[n].pb(u);
            adj[u].pb(n);
            adj[n].pb(v);
            adj[v].pb(n);
        }
        else
        {
            adj[v].pb(u);
            adj[u].pb(v);
        }
    }
    bool isbi = true;
    queue<lli> q;
    for (int i = 1; i <= n; i++)
    {
        if (color[i] == -1)
        {
            q.push(i);
            color[i] = 0;
            while (!q.empty())
            {
                lli s = q.front();
                q.pop();
                for (auto u : adj[s])
                {
                    if (color[u] == -1)
                    {
                        color[u] = 1 - color[s];
                        q.push(u);
                    }
                    else
                    {
                        isbi &= (color[u] != color[s]);
                    }
                }
            }
        }
    }
    if (isbi)
        cout << "NO";
    else
        cout << "YES";
    return 0;
}