# |
Submission time |
Handle |
Problem |
Language |
Result |
Execution time |
Memory |
704936 |
2023-03-03T07:01:00 Z |
PikaQ |
Naboj (COCI22_naboj) |
C++17 |
|
218 ms |
32876 KB |
#include<bits/stdc++.h>
#define int long long
#define forn(i,n) for(int i = 0;i < n;i++)
#define Forn(i,n) for(int i = 1;i <= n;i++)
#define vi vector<int>
#define pb push_back
#define pii pair<int,int>
#define all(p) p.begin(),p.end()
#define F first
#define S second
using namespace std;
void debug() {cerr << endl;}
template <class T, class ...U> void debug(T a, U ... b) { cerr << a << " "; debug(b...);}
const int INF = 1e13 + 10;
const int MOD = (int) 998244353;
const int N = 2e5 + 9;
int n,m;
vi e1[N];
vector<pii> e2[N];
int in[N],out[N];
vector<pii> ans;
queue<int> que;
bool vis[N];
bool tag[N];
void dfs(int u,int tp){
//debug(u,tp,"??");
vis[u] = 1;
ans.pb({u,tp});
if(tp == 1) tp = 0;
else tp = 1;
for(auto [c,w] : e2[u]){
if(!vis[c]){
dfs(c,w);
}
}
}
bool dfsc(int u){
//debug(u);
vis[u] = 1;
tag[u] = 1;
bool ok = 0;
for(int c : e1[u]){
if(tag[c]) ok = 1;
else if(vis[c]) continue;
else ok |= dfsc(c);
}
tag[u] = 0;
return ok;
}
void solve(){
//pancake ( ^-^)_
cin >> n >> m;
forn(i,m){
int s,t;
cin >> s >> t;
out[s]++,in[t]++;
e1[s].pb(t);
e2[s].pb({t,1});
e2[t].pb({s,0});
}
//debug("?");
Forn(i,n) if(!vis[i] && dfsc(i)) {
assert(0);
cout << "-1\n";
return ;
}
Forn(i,n) vis[i] = 0;
Forn(i,n){
if(!vis[i] && out[i]) dfs(i,0);
else if(!vis[i] && in[i]) dfs(i,1);
}
cout << ans.size() << '\n';
forn(i,ans.size()){
cout << ans[i].F << ' ' << ans[i].S << '\n';
}
}
signed main(){
cin.tie(NULL);
cout.tie(NULL);
ios_base::sync_with_stdio(0);
solve();
return 0;
}
Compilation message
naboj.cpp: In function 'void solve()':
naboj.cpp:3:35: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
3 | #define forn(i,n) for(int i = 0;i < n;i++)
......
76 | forn(i,ans.size()){
| ~~~~~~~~~~~~
naboj.cpp:76:2: note: in expansion of macro 'forn'
76 | forn(i,ans.size()){
| ^~~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
13 ms |
19496 KB |
Execution killed with signal 6 |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
218 ms |
32876 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
13 ms |
19496 KB |
Execution killed with signal 6 |
2 |
Halted |
0 ms |
0 KB |
- |