GraphDS/BipartiteCheck.cpp at main · vivekko/GraphDS · GitHub

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#include <bits/stdc++.h>
using namespace std;
void __print(int x) { cerr << x; }
void __print(long x) { cerr << x; }
void __print(long long x) { cerr << x; }
void __print(unsigned x) { cerr << x; }
void __print(unsigned long x) { cerr << x; }
void __print(unsigned long long x) { cerr << x; }
void __print(float x) { cerr << x; }
void __print(double x) { cerr << x; }
void __print(long double x) { cerr << x; }
void __print(char x) { cerr << '\'' << x << '\''; }
void __print(const char *x) { cerr << '\"' << x << '\"'; }
void __print(const string &x) { cerr << '\"' << x << '\"'; }
void __print(bool x) { cerr << (x ? "true" : "false"); }
#define NFS(nitro)                    \
    ios_base::sync_with_stdio(false); \
    cin.tie(0);
template <typename T, typename V>
void __print(const pair<T, V> &x)
{
    cerr << '{';
    __print(x.first);
    cerr << ',';
    __print(x.second);
    cerr << '}';
}
template <typename T>
void __print(const T &x)
{
    int f = 0;
    cerr << '{';
    for (auto &i : x)
        cerr << (f++ ? "," : ""), __print(i);
    cerr << "}";
}
void _print() { cerr << "]\n"; }
template <typename T, typename... V>
void _print(T t, V... v)
{
    __print(t);
    if (sizeof...(v))
        cerr << ", ";
    _print(v...);
}
#ifndef ONLINE_JUDGE
#define debug(x...)               \
    cerr << "[" << #x << "] = ["; \
    _print(x)
#else
#define debug(x...)
#endif
#define int long long
#define vivek main
#define all(x) (x).begin(), (x).end()
#define vec_p vector < pair<int, int>
#define v vector<int>
bool bip(int i, v adj[], v &colour)
{
    queue<int> q;
    q.push(i);
    colour[i] = 1;
    while (!q.empty())
    {
        int node = q.front();
        q.pop();
        for (auto i : adj[node])
        {
            if (colour[i] == -1)
            {
                colour[i] = 1 - colour[node];
                q.push(i);
            }
            else if (colour[i] == colour[node])
            {
                return false;
            }
        }
    }
    return true;
}

bool checkBipartite(v adj[], int n)
{
    v colour(n + 1, -1);
    for (int i = 1; i <= n; i++)
    {
        if (colour[i] != -1)
        {
            if (!bip(i, adj, colour))
                return false;
        }
    }
    return true;
}

void solve()
{
    int m, n;
    cin >> m >> n;
    v adj[n + 1];
    for (int i = 1; i <= n; i++)
    {
        int x, y;
        cin >> x >> y;
        adj[x].push_back(y);
        adj[y].push_back(x);
    }
    checkBipartite(adj, n);
}
int32_t vivek()
{
    NFS(NITRO);
    int t;
    cin >> t;
    while (t-- > 0)
        solve();
    return 0;
}

// ___.   .__                 __          .__              __
// \_ |__ |  | _____    ____ |  | _____  _|__|__  __ ____ |  | __
//  | __ \|  | \__  \ _/ ___\|  |/ /\  \/ /  \  \/ // __ \|  |/ /
//  | \_\ \  |__/ __ \   \___|    <  \   /|  |\   /\  ___/|    <
//  |___  /____(____  /\___  >__|_ \  \_/ |__| \_/  \___  >__|_ \
//      \/          \/     \/     \/                    \/     \/