oj.uz

Submission #54887

# Submission time Handle Problem Language Result Execution time Memory
54887 2018-07-05T08:54:23 Z 김세빈(#1509) Pipes (CEOI15_pipes) C++11
100 / 100
 1610 ms 8028 KB 
#include <bits/stdc++.h>

using namespace std;

typedef pair<int,int> pii;

vector <int> V[101010], T;
int P[101010], K[101010];
int R[101010], D[101010], S[101010];
bool chk[101010];
int n, m;

void reorder(int x, int p, int r, int f)
{
	int i, c;
	
	D[p] = D[r] + 1; R[p] = x;
	c = K[p], K[p] = P[p] = r;
	
	for(auto t: V[p]){
		if(t != r){
			if(t == c) reorder(x, t, p, chk[p]);
			else reorder(x, t, p, 0);
		}
	}
	
	if(c != r) chk[p] = f;
}

void check(int a, int b)
{
	T.clear();
	for(;a!=b;){
		if(D[a] < D[b]){
			T.push_back(b);
			b = P[b];
		}
		else{
			T.push_back(a);
			a = P[a];
		}
	}
	
	for(auto t: T) P[t] = a, chk[t] = 1;
}

int main()
{
	int i, a, b;
	
	scanf("%d%d", &n, &m);
	
	for(i=1;i<=n;i++){
		S[i] = 1;
		R[i] = i;
	}
	
	for(i=1;i<=m;i++){
		scanf("%d%d", &a, &b);
		if(R[a] != R[b]){
			if(S[R[a]] > S[R[b]]) swap(a, b);
			
			V[a].push_back(b);
			V[b].push_back(a);
			
			S[R[b]] += S[R[a]];
			reorder(R[b], a, b, 0);
		}
		else check(a, b);
	}
	
	for(i=1;i<=n;i++){
		if(R[i] != i && !chk[i]) printf("%d %d\n", i, K[i]);
	}
	
	return 0;
}

Compilation message

pipes.cpp: In function 'void reorder(int, int, int, int)':
pipes.cpp:15:6: warning: unused variable 'i' [-Wunused-variable]
  int i, c;
      ^
pipes.cpp: In function 'int main()':
pipes.cpp:51:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d", &n, &m);
  ~~~~~^~~~~~~~~~~~~~~~
pipes.cpp:59:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d", &a, &b);
   ~~~~~^~~~~~~~~~~~~~~~

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 2688 KB Output is correct
2 Correct 4 ms 2688 KB Output is correct

Subtask #2
10.0 / 10.0

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

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 119 ms 2916 KB Output is correct
2 Correct 118 ms 2928 KB Output is correct

Subtask #4
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 209 ms 3172 KB Output is correct
2 Correct 248 ms 3248 KB Output is correct

Subtask #5
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 353 ms 3940 KB Output is correct
2 Correct 305 ms 4252 KB Output is correct

Subtask #6
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 496 ms 6376 KB Output is correct
2 Correct 462 ms 6404 KB Output is correct

Subtask #7
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 779 ms 6932 KB Output is correct
2 Correct 837 ms 6896 KB Output is correct

Subtask #8
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1089 ms 7800 KB Output is correct
2 Correct 1038 ms 8028 KB Output is correct

Subtask #9
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1325 ms 7800 KB Output is correct
2 Correct 1249 ms 7940 KB Output is correct

Subtask #10
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1610 ms 7544 KB Output is correct
2 Correct 1540 ms 7928 KB Output is correct