Submission #948340

#	Time	Username	Problem	Language	Result	Execution time	Memory
948340		vjudge1	Pipes (CEOI15_pipes)	C++17	20 / 100	410 ms	65536 KiB

pipes

#include <bits/stdc++.h>
#define ll long long
#define str string
#define ins insert
#define ld long double
#define pb push_back
#define pf push_front
#define pof pop_front()
#define pob pop_back()
#define lb lower_bound
#define ub upper_bound
#define endl "\n"
#define fr first
#define sc second
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define sz size()
#define vll vector<ll>
#define bc back()
#define arr array
#define pll vector<pair<ll,ll>>
using namespace std;/*
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
#define ordered_set tree<ll, null_type,less_equal<ll>, rb_tree_tag,tree_order_statistics_node_update>*/
template<class S,class T>
bool chmin(S &a,const T &b) {
	return a>b?(a=b)==b:false;
}
template<class S,class T>
bool chmax(S &a,const T &b) {
	return a<b?(a=b)==b:false;
}
void start(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
}
const ll inf=1e18;
const ll mod=1e9+7;
const ll N=1e5+5;
const ll M=6e6+5;
const ld eps=1e-9;
vector<vll> g(N);
ll d[N],up[N];
pair<ll,ll> e[M];
ll br[M];
void dfs(ll v,ll x){
    ll i,b;
    up[v]=d[v];
    for(i=0;i<g[v].sz;i++){
        if(g[v][i]==x) continue;
        if(e[g[v][i]].fr==v) b=e[g[v][i]].sc;
        else b=e[g[v][i]].fr;
        if(d[b]){chmin(up[v],d[b]);continue;}
        d[b]=d[v]+1;
        dfs(b,g[v][i]);
        chmin(up[v],up[b]);
    }
    if(up[v]>=d[v])br[x]=1;
}
void solve(){
    ll i,j;
    ll n,m,a,b;
    cin>>n>>m;
    for(i=1;i<=m;i++){
        cin>>e[i].fr>>e[i].sc;
        g[e[i].fr].pb(i);
        g[e[i].sc].pb(i);
    }
    for(i=1;i<=n;i++){
        if(!d[i]){
            d[i]=1;
            dfs(i,0);
        }
    }
    for(i=1;i<=m;i++){
        if(br[i]) cout<<e[i].fr<<' '<<e[i].sc<<endl;
    }
}

signed main(){
	start();
    ll t=1;
    //cin>>t;
    while(t--) solve();
    return 0;
}
/*




*/

Compilation message (stderr)

pipes.cpp: In function 'void dfs(long long int, long long int)':
pipes.cpp:52:14: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   52 |     for(i=0;i<g[v].sz;i++){
      |              ^
pipes.cpp: In function 'void solve()':
pipes.cpp:64:10: warning: unused variable 'j' [-Wunused-variable]
   64 |     ll i,j;
      |          ^
pipes.cpp:65:12: warning: unused variable 'a' [-Wunused-variable]
   65 |     ll n,m,a,b;
      |            ^
pipes.cpp:65:14: warning: unused variable 'b' [-Wunused-variable]
   65 |     ll n,m,a,b;
      |              ^

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 0 / 10
• Subtask 4: 0 / 10
• Subtask 5: 0 / 10
• Subtask 6: 0 / 10
• Subtask 7: 0 / 10
• Subtask 8: 0 / 10
• Subtask 9: 0 / 10
• Subtask 10: 0 / 10