Submission #115966

#	Time	Username	Problem	Language	Result	Execution time	Memory
115966		Mahdi_Jfri	Senior Postmen (BOI14_postmen)	C++14	100 / 100	342 ms	43480 KiB

postmen

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

#define ll long long
#define pb push_back

const int maxn = 1e6 + 20;

vector<int> path;

int from[maxn] , to[maxn] , last[maxn] , head[maxn] , id;

bool visited[maxn];

void add_edge(int v , int u)
{
	from[id] = v , to[id] = u , last[id] = head[v] , head[v] = id , id++;
	from[id] = u , to[id] = v , last[id] = head[u] , head[u] = id , id++;
}

void dfs(int v)
{
	while(head[v] != -1)
	{
		int e = head[v] , u = to[e];
		head[v] = last[e];

		if(visited[e / 2])
			continue;

		visited[e / 2] = 1;
		dfs(u);
	}
	path.pb(v);
}

int main()
{
	memset(head , -1 , sizeof head);
	int n , m;
	scanf("%d%d", &n, &m);

	for(int i = 0; i < m; i++)
	{
		int a , b;
		scanf("%d%d", &a, &b);
		a-- , b--;

		add_edge(a , b);
	}

	dfs(0);

	vector<int> tmp;
	memset(visited , 0 , sizeof visited);
	for(auto v : path)
	{
		if(visited[v])
		{
			while(tmp.back() != v)
			{
				printf("%d ", tmp.back() + 1);
				visited[tmp.back()] = 0;
				tmp.pop_back();
			}
			tmp.pop_back();
			printf("%d\n", v + 1);
		}

		tmp.pb(v);
		visited[v] = 1;
	}
}

Compilation message (stderr)

postmen.cpp: In function 'int main()':
postmen.cpp:41:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d", &n, &m);
  ~~~~~^~~~~~~~~~~~~~~~
postmen.cpp:46:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d", &a, &b);
   ~~~~~^~~~~~~~~~~~~~~~

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