Submission #34382

#	Time	Username	Problem	Language	Result	Execution time	Memory
34382		mohammad_kilani	Pipes (CEOI15_pipes)	C++14	30 / 100	517 ms	13300 KiB

pipes

#include <bits/stdc++.h>
using namespace std;
#define mod 1000007
#define oo 2000000000
const int M = 1500010 , N = 30011;
bitset< N > vis;
vector< short > g[N];
short dfs_low[N], dfs_num[N], num = 0 ;
int n , m , u , v , ans = 0 ;

void DFS(short node,short prnt){
	vis[node] = true;
	dfs_low[node] = dfs_num[node] = num++;
	for(short i=0;i<g[node].size();i++){
		if(g[node][i] == prnt) continue;
		if(vis[g[node][i]]){
			dfs_low[node] = min(dfs_low[node],dfs_num[g[node][i]]);
		}
		else{
			DFS(g[node][i],node);
			if(dfs_num[node] < dfs_low[g[node][i]]){
				++ans; 
				printf("%d %d\n",min(node,g[node][i]),max(node,g[node][i]));
			}
			dfs_low[node] = min(dfs_low[node],dfs_low[g[node][i]]);
		}
	}
}

int main() {
	//freopen("in.txt","r",stdin);
	scanf("%d%d",&n,&m);
	for(int i=0;i<m;i++){
		scanf("%d%d",&u,&v);
		g[u].push_back(v);
		g[v].push_back(u);
	}
	for(short i=1;i<=n;i++){
		if(vis[i] == false) DFS(i,-1);
	}
	if(ans == 0) puts("");
	return 0;
}

Compilation message (stderr)

pipes.cpp: In function 'void DFS(short int, short int)':
pipes.cpp:14:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(short i=0;i<g[node].size();i++){
                ~^~~~~~~~~~~~~~~
pipes.cpp: In function 'int main()':
pipes.cpp:32:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d",&n,&m);
  ~~~~~^~~~~~~~~~~~~~
pipes.cpp:34:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d",&u,&v);
   ~~~~~^~~~~~~~~~~~~~

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