Codeforces/Codeforces 1217D.cpp at master · jvillegasd/Codeforces · GitHub

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#include <bits/stdc++.h>
#define pb push_back
#define pf push_front
#define pob pop_back
#define fp first
#define sp second
#define mp make_pair
#define ins insert
#define uEdge(u, v) g[u].pb(v), g[v].pb(u)
#define uwEdge(u, v, w) g[u].pb({v, w}), g[v].pb({u, w})
#define dEdge(u, v) g[u].pb(v)
#define dEdger(u, v) rg[u].pb(v)
#define dwEdge(u, v, w) g[u].pb({v, w})
#define BOOST ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0)
#define minHeap int, vector<int>, greater<int>
#define MOD 1000000007

using namespace std;
typedef long long int lli;
typedef pair<int, int> pii;
lli nl, arr[0];
vector<pii> g[5010];
int c[5010], rs[5010];
bool cycle=0;

lli gcd(lli a, lli b){if(b == 0) return a;a%=b;return gcd(b, a);}
lli lcm(lli a, lli b){return (a*b)/gcd(a, b);}
int bs(lli sum){int l=0,r=nl-1,mid;while(l<=r){mid=(l+r)/2;if(arr[mid]==sum)return mid;if(arr[mid]<sum)l=mid+1;else r=mid-1;}return -1;}
lli modPow(lli a, lli b){a%=MOD;lli ans=1;while(b > 0){if(b & 1) ans=ans*a%MOD;a=a*a%MOD;b>>=1;}return ans;}

void DFS(int u){
    rs[u]=1;
    for(auto e : g[u]){
        int v=e.fp, id=e.sp;
        if(rs[v] == 0){
            DFS(v);
            c[id]=1;
        }else if(rs[v] == 2){
            c[id]=1;
        }else{
            cycle=1;
            c[id]=2;
        }
    }
    rs[u]=2;
}

int main(){
    int n, m, u, v;
    scanf("%d %d", &n, &m);
    for(int i = 0; i < m; i++) scanf("%d %d", &u, &v), g[u].pb({v, i});
    memset(c, 0, sizeof(c));
    memset(rs, 0, sizeof(rs));
    for(u = 1; u <= n; u++) if(rs[u] == 0) DFS(u);
    printf("%d\n", (cycle)?2:1);
    for(int i = 0; i < m; i++) printf("%d ", c[i]);
    return 0;
}