Submission #291920

#	Time	Username	Problem	Language	Result	Execution time	Memory
291920		anonymous	Senior Postmen (BOI14_postmen)	C++14	55 / 100	531 ms	56056 KiB

postmen

#include <iostream>
#include <vector>
#include <utility>
#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#pragma GCC optimize("unroll-loops")
#define MAXN 500005
using namespace std;
int N, M, del[MAXN], inStack[MAXN];
vector <pair<int,int> > adj[MAXN];
vector <int> S,S2;
 
void dfs(int u) { //Hierholzer
    while (adj[u].size()) {
        int v = adj[u].back().first, id = adj[u].back().second;
        adj[u].pop_back();
        if (!del[id]) {
            del[id] = true;
            dfs(v);
        }
    }
    S.push_back(u);
}
 
int main() {
    //freopen("seniorin.txt","r",stdin);
    scanf("%d %d",&N,&M);
    for (int i=1; i<=M; i++) {
        int u,v;
        scanf("%d %d",&u,&v);
        adj[u].push_back({v,i});
        adj[v].push_back({u,i});
    }
  	S.reserve(2*N), S2.reserve(2*N);
  	
    dfs(1);
    for (int i=0; i<S.size(); i++) {
        if (inStack[S[i]]) {
            while (S2.size() && S2.back() != S[i]) {
                printf("%d ",S2.back());
                inStack[S2.back()]--;
                S2.pop_back();
            }
            printf("%d\n",S[i]);
        } else {
            inStack[S[i]]++;
            S2.push_back(S[i]);
        }
    }
}

Compilation message (stderr)

postmen.cpp: In function 'int main()':
postmen.cpp:37:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   37 |     for (int i=0; i<S.size(); i++) {
      |                   ~^~~~~~~~~
postmen.cpp:27:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   27 |     scanf("%d %d",&N,&M);
      |     ~~~~~^~~~~~~~~~~~~~~
postmen.cpp:30:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   30 |         scanf("%d %d",&u,&v);
      |         ~~~~~^~~~~~~~~~~~~~~

• Subtask 1: 38 / 38
• Subtask 2: 17 / 17
• Subtask 3: 0 / 45