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Submission #49178

# Submission time Handle Problem Language Result Execution time Memory
49178 2018-05-23T06:32:57 Z Namnamseo Pipes (CEOI15_pipes) C++17
100 / 100
 1449 ms 12488 KB 
#include <cstdio>
#include <vector>
using namespace std;
#define pb push_back
typedef pair<int,int> pp;

int n, m;

struct unf {
	int par[100010];
	void init(){ for(int i=1; i<=n; ++i) par[i]=i; }

	int root(int x){ return (x==par[x])?x:(par[x]=root(par[x])); }
	bool merge(int a,int b){
		a=root(a); b=root(b);
		if(a==b) return false;
		par[a]=b;
		return true;
	}
} f1, f2;

int par[100010];
int idx[100010];
int lowl[100010];
int nt;
vector<int> edge[100010];

void dfs(int x){
	idx[x] = lowl[x] = ++nt;
	bool cl = false;
	for(int y:edge[x]){
		if(par[x] == y && !cl){
			cl=true; continue;
		}
		if(!idx[y]){
			par[y]=x;
			dfs(y);
			lowl[x] = min(lowl[x], lowl[y]);
		} else lowl[x] = min(lowl[x], idx[y]);
	}
	if(par[x] && idx[x]==lowl[x]) printf("%d %d\n", x, par[x]);
}

int main(){
	scanf("%d%d", &n, &m);
	f1.init(); f2.init();
for(;m--;){
	int a,b;
	scanf("%d%d", &a, &b);
	if(f1.merge(a,b) || f2.merge(a,b)) edge[a].pb(b), edge[b].pb(a);
}
	for(int i=1; i<=n; ++i) if(par[i]==0) dfs(i);
	return 0;
}

Compilation message

pipes.cpp: In function 'int main()':
pipes.cpp:45:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d", &n, &m);
  ~~~~~^~~~~~~~~~~~~~~~
pipes.cpp:49:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d", &a, &b);
  ~~~~~^~~~~~~~~~~~~~~~

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 2660 KB Output is correct
2 Correct 3 ms 2688 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 3072 KB Output is correct
2 Correct 8 ms 2944 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 111 ms 3008 KB Output is correct
2 Correct 108 ms 2936 KB Output is correct

Subtask #4
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 195 ms 3572 KB Output is correct
2 Correct 229 ms 3320 KB Output is correct

Subtask #5
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 323 ms 5004 KB Output is correct
2 Correct 279 ms 4868 KB Output is correct

Subtask #6
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 492 ms 9532 KB Output is correct
2 Correct 405 ms 7160 KB Output is correct

Subtask #7
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 825 ms 10648 KB Output is correct
2 Correct 688 ms 8684 KB Output is correct

Subtask #8
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 995 ms 12488 KB Output is correct
2 Correct 882 ms 9164 KB Output is correct

Subtask #9
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1186 ms 12476 KB Output is correct
2 Correct 1154 ms 9164 KB Output is correct

Subtask #10
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1449 ms 11968 KB Output is correct
2 Correct 1385 ms 9976 KB Output is correct