Submission #292211

#	Time	Username	Problem	Language	Result	Execution time	Memory
292211		davooddkareshki	Senior Postmen (BOI14_postmen)	C++17	55 / 100	557 ms	58856 KiB

postmen

#include<bits/stdc++.h>
using namespace std;

//#define int long long
#define F first
#define S second
#define pii pair<int,int>
#define mpr make_pair

#pragma GCC optimize("O1")
#pragma GCC optimize("O2")
#pragma GCC optimize("O3")
#pragma GCC optimize("O4")
#pragma GCC optimize("O5")
#pragma GCC optimize("O6")
#pragma GCC optimize("O7")
#pragma GCC optimize("O8")
#pragma GCC optimize("O9")
#pragma GCC optimize("Ofast")

typedef long long ll;

const int maxn = 5e5+1;
const int mod = 1e9+7;

int n, m, k;
bitset<maxn> mark_E;
vector<pii> g[maxn];
int ptr[maxn];

bitset<maxn> mark;
vector<int> stk;
bool yes;

void DO(int v)
{
    if(mark[v])
    {
        while(stk.back() != v)
        {
            int u = stk.back();
            mark[u] = 0;
            printf("%d ", u);
            stk.pop_back();
        }
        mark[v] = 0;
        if(yes) printf("%d", v);
        else printf("%d\n", v);
        stk.pop_back();
    }
    mark[v] = 1;
    stk.push_back(v);
}

void dfs(int v)
{
    for(; ptr[v] < g[v].size(); ptr[v]++)
    {
        pii e = g[v][ptr[v]];
        int u = e.F, id = e.S;
        if(!mark_E[id])
        {
            mark_E[id] = 1;
            dfs(u);
            DO(u);
        }
    }
}

signed main()
{
    //ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);

    scanf("%d%d", &n, &m);
    for(int i = 1, u, v; i <= m; i++)
    {
        scanf("%d%d", &u, &v);
        g[u].push_back({v,i});
        g[v].push_back({u,i});
    }

    dfs(1);
    yes = 1;
    DO(1);
}
/*
10 15
1 3
5 1
2 3
9 2
3 4
6 3
4 5
7 4
4 8
5 7
8 5
6 7
7 8
8 10
10 9
*/

Compilation message (stderr)

postmen.cpp: In function 'void dfs(int)':
postmen.cpp:57:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   57 |     for(; ptr[v] < g[v].size(); ptr[v]++)
      |           ~~~~~~~^~~~~~~~~~~~~
postmen.cpp: In function 'int main()':
postmen.cpp:74:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   74 |     scanf("%d%d", &n, &m);
      |     ~~~~~^~~~~~~~~~~~~~~~
postmen.cpp:77:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   77 |         scanf("%d%d", &u, &v);
      |         ~~~~~^~~~~~~~~~~~~~~~

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