oj.uz

Submission #27159

# Submission time Handle Problem Language Result Execution time Memory
27159 2017-07-09T17:23:35 Z bill_kondo Pipes (CEOI15_pipes) C++14
20 / 100
 2056 ms 13948 KB 
#include "bits/stdc++.h"
using namespace std;

#define pb push_back
#define debug(args...) fprintf(stderr,args)
#define FOR(i,a,b) for(int i = a; i <= b; ++i)
#define REP(i,a,b) for(int i = a; i >= b; --i)

typedef long long ll;
typedef pair<int,int>pii;

const int maxn = 1e5 + 10;

static int n, m;

struct dsu{
	int par[maxn];
	int sz[maxn];

	void init(){
		FOR(i,1,n){
			par[i] = i;
			sz[i] = 1;
		}
	}

	int root(int v){
		if(par[v] == v) return v;
		return root(par[v]);
	}

	void merge(int x, int y){
		x = root(x);
		y = root(y);
		if(x == y) return;
		if(sz[y] > sz[x]) swap(x,y);
		par[y] = x;
		sz[x] += sz[y];
	}

} T[2];

vector<int>adj[maxn];

static int h[maxn], low[maxn], cur;
static bool mrk[maxn];

void dfs(int v, int par){
	mrk[v] = true;
	low[v] = h[v] = ++cur;
	for(int i = 0; i < adj[v].size(); ++i){
		int u = adj[v][i];
		if(u == par) continue;
		if(!mrk[u]){
			dfs(u,v);
			low[v] = min(low[v],low[u]);
			if(low[u] > h[v]) printf("%d %d\n",u,v);
		}
		else low[v] = min(low[v],h[u]);
	}
}

void tarjan(){
	FOR(i,1,n)
		if(!mrk[i])
			dfs(i,-1);
}

int main(){
	scanf("%d%d",&n,&m);

	T[0].init();
	T[1].init();

	FOR(i,1,m){
		int a, b;
		scanf("%d%d",&a,&b);
		if(T[0].root(a) != T[0].root(b)){	
			adj[a].pb(b);
			adj[b].pb(a);
			T[0].merge(a,b);
		}
		else if(T[1].root(a) != T[1].root(b)){
			adj[a].pb(b);
			adj[b].pb(a);
			T[1].merge(a,b);
		}
	}
	tarjan();
	return 0;
}

Compilation message

pipes.cpp: In function 'void dfs(int, int)':
pipes.cpp:51:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0; i < adj[v].size(); ++i){
                 ~~^~~~~~~~~~~~~~~
pipes.cpp: In function 'int main()':
pipes.cpp:70:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d",&n,&m);
  ~~~~~^~~~~~~~~~~~~~
pipes.cpp:77:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d",&a,&b);
   ~~~~~^~~~~~~~~~~~~~

Subtask #1
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 2688 KB Output is correct
2 Incorrect 4 ms 2688 KB Wrong number of edges

Subtask #2
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 3172 KB Output is correct
2 Incorrect 8 ms 3072 KB Wrong number of edges

Subtask #3
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 141 ms 3064 KB Output is correct
2 Incorrect 154 ms 2920 KB Wrong number of edges

Subtask #4
0 / 10.0

# Verdict Execution time Memory Grader output
1 Incorrect 252 ms 3784 KB Wrong number of edges
2 Halted 0 ms 0 KB -

Subtask #5
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 420 ms 5336 KB Output is correct
2 Correct 355 ms 5112 KB Output is correct

Subtask #6
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 597 ms 10608 KB Output is correct
2 Incorrect 528 ms 7664 KB Wrong number of edges

Subtask #7
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 952 ms 11872 KB Output is correct
2 Incorrect 917 ms 9232 KB Wrong number of edges

Subtask #8
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1374 ms 13948 KB Output is correct
2 Incorrect 1272 ms 9828 KB Wrong number of edges

Subtask #9
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1683 ms 13916 KB Output is correct
2 Incorrect 1549 ms 9824 KB Wrong number of edges

Subtask #10
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 2056 ms 13360 KB Output is correct
2 Correct 1844 ms 10948 KB Output is correct