oj.uz

Submission #24679

# Submission time Handle Problem Language Result Execution time Memory
24679 2017-06-11T15:52:36 Z Bruteforceman Pipes (CEOI15_pipes) C++11
100 / 100
 1607 ms 13792 KB 
#include "bits/stdc++.h"
using namespace std;

int *par;
int *bic;
vector <int> *g;
int *low, *disc;
bitset <100005> vis;
vector <int> l, r;

int rootPar(int x) {
	if(par[x] == x) return x;
	return par[x] = rootPar(par[x]);
}
int rootBic(int x) {
	if(bic[x] == x) return x;
	return bic[x] = rootBic(bic[x]);
}

void joinPar(int x, int y) {
	x = rootPar(x);
	y = rootPar(y);
	if(x != y) {
		par[x] = y;
	}
}
void joinBic(int x, int y) {
	x = rootBic(x);
	y = rootBic(y);
	if(x != y) {
		bic[x] = y;
	}
}

int tym;
void dfs(int x, int parent) {
	vis[x] = 1;
	low[x] = disc[x] = ++tym;
	bool see = false;
	for(auto i : g[x]) {
		if (!see && i == parent) {
			see = true;
			continue;
		}
		if(vis[i] == 0) {
			dfs(i, x);
			low[x] = min(low[x], low[i]);
			if(disc[x] < low[i]) {
				l.push_back(x);
				r.push_back(i);
			}
		} else if (vis[i] == 1) {
			low[x] = min(low[x], disc[i]);
		}
	}
}

int main(int argc, char const *argv[])
{
	int n, m;
	scanf("%d %d", &n, &m);

	par = new int [n + 5];
	bic = new int [n + 5];

	for(int i = 1; i <= n; i++) {
		par[i] = i;
		bic[i] = i;
	}
	for(int i = 1; i <= m; i++) {
		int p, q;
		scanf("%d %d", &p, &q);
		if(rootPar(p) != rootPar(q)) {
			joinPar(p, q);
			l.push_back(p);
			r.push_back(q);
		} else if (rootBic(q) != rootBic(p)) {
			joinBic(p, q);
			l.push_back(p);
			r.push_back(q);
		}
	}

	delete par;
	delete bic;

	g = new vector <int> [n + 5];
	for(size_t i = 0; i < l.size(); i++) {
		g[l[i]].push_back(r[i]);
		g[r[i]].push_back(l[i]);
	}
	l.clear();
	r.clear();

	low = new int [n + 5];
	disc = new int [n + 5];

	for(int i = 1; i <= n; i++) {
		if(vis[i] == 0) {
			dfs(i, 0);
		}
	}	
	for(size_t i = 0; i < l.size(); i++) {
		printf("%d %d\n", l[i], r[i]);
	}
	delete low;
	delete disc;
	return 0;
}

Compilation message

pipes.cpp: In function 'int main(int, const char**)':
pipes.cpp:61:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d", &n, &m);
  ~~~~~^~~~~~~~~~~~~~~~~
pipes.cpp:72:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d", &p, &q);
   ~~~~~^~~~~~~~~~~~~~~~~

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 256 KB Output is correct
2 Correct 2 ms 256 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 1024 KB Output is correct
2 Correct 6 ms 768 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 120 ms 724 KB Output is correct
2 Correct 118 ms 596 KB Output is correct

Subtask #4
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 211 ms 1632 KB Output is correct
2 Correct 251 ms 1272 KB Output is correct

Subtask #5
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 345 ms 3568 KB Output is correct
2 Correct 289 ms 3320 KB Output is correct

Subtask #6
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 493 ms 9876 KB Output is correct
2 Correct 469 ms 7020 KB Output is correct

Subtask #7
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 769 ms 11192 KB Output is correct
2 Correct 729 ms 8628 KB Output is correct

Subtask #8
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1018 ms 13792 KB Output is correct
2 Correct 957 ms 9696 KB Output is correct

Subtask #9
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1255 ms 13780 KB Output is correct
2 Correct 1282 ms 9704 KB Output is correct

Subtask #10
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1607 ms 13072 KB Output is correct
2 Correct 1437 ms 10448 KB Output is correct