Submission #1184467

#	Time	Username	Problem	Language	Result	Execution time	Memory
1184467		sasde	Pipes (BOI13_pipes)	C++20	30 / 100	663 ms	196608 KiB

pipes

#include<bits/stdc++.h>
#define task "strdel"
#define int long long
#define ii pair<int,int>
#define iii pair<int,ii>
#define iv pair<ii,ii>
#define se second
#define fi first
#define ffi fi.fi
#define sfi se.fi
#define sse se.se
#define fse fi.se
#define lt(i, c, d) for(int i = c; i <= d; ++i)
#define fl(i, c, d) for(int i = d; i >= c; --i)
#define pb push_back
#define emb emplace_back
#define emf emplace_front
#define em emplace
using namespace std;
const int N=1e6+5,lg=20,mod=1e9+7;
mt19937 rd(chrono::steady_clock::now().time_since_epoch().count());
int Rand(int u,int v){
 return u+rd()%(v-u+1);
}
int c[N],m,n,d[N],up[N],sum[N],ans[N];
ii b[N];
vector<ii>a[N];
void dfs(int u,int cha){
    d[u]=c[u];
    for(ii v:a[u]){
        if(v.fi==cha)continue;
        up[v.fi]=v.se;
        dfs(v.fi,u);
        d[u]-=d[v.fi];
    }
}
void solve(){
    cin >> n >> m;
    for(int i=1;i<=n;++i)cin >> c[i];
        for(int i=1;i<=m;++i){
            int u,v;
            cin >> u >> v;
            b[i]={u,v};
            a[u].emb(v,i);
            a[v].emb(u,i);
        }
    dfs(1,-1);
    for(int i=1;i<=n;++i){
        int u=up[i];
        sum[b[u].fi]+=d[i];
        ans[u]=d[i];
        sum[b[u].se]+=d[i];
    }
    for(int i=1;i<=n;++i){
        if(sum[i]!=c[i]){
            cout <<0;return;
        }
    }
    for(int i=1;i<=m;++i)cout <<ans[i]*2<<'\n';
    
}
main()
{
  srand(time(0));
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    if(fopen(task".inp","r")){
      freopen(task".inp","r",stdin);
      freopen(task".out","w",stdout);
    }
    int t=1;
 //   cin >> t;
while(t--){
    solve();
    // cout<<'\n';
}

}

Compilation message (stderr)

pipes.cpp:62:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   62 | main()
      | ^~~~
pipes.cpp: In function 'int main()':
pipes.cpp:69:14: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   69 |       freopen(task".inp","r",stdin);
      |       ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
pipes.cpp:70:14: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   70 |       freopen(task".out","w",stdout);
      |       ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 30 / 30
• Subtask 2: 0 / 70