oj.uz

Submission #127058

# Submission time Handle Problem Language Result Execution time Memory
127058 2019-07-08T20:42:20 Z Lawliet Mousetrap (CEOI17_mousetrap) C++14
25 / 100
 1127 ms 69532 KB 
#include <bits/stdc++.h>

#define MAX 1000010

using namespace std;
typedef long long int lli;

int n;
int mouse, trap;
int n1, n2;

int pai[MAX];

lli dp[MAX];

vector<int> grafo[MAX];

void DFS(int i, int p)
{
	if(grafo[i].size() == 1 && i != trap)
	{
		dp[i] = 0;
		return;
	}

	vector<int> aux;

	aux.push_back( 0 );

	for(int g = 0 ; g < grafo[i].size() ; g++)
	{
		int prox = grafo[i][g];

		if(prox == p) continue;

		pai[prox] = i;

		//printf("i = %d  prox = %d\n",i,prox);

		DFS(prox , i);

		aux.push_back( dp[prox] );
	}

	sort(aux.begin() , aux.end());

	dp[i] = grafo[i].size() - 2 + aux[aux.size() - 2] + 1;

	//printf("dp(%d) = %lld\n",i,dp[i]);
}

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

	for(int g = 0 ; g < n - 1 ; g++)
	{
		scanf("%d %d",&n1,&n2);

		grafo[n1].push_back(n2);
		grafo[n2].push_back(n1);
	}

	DFS(trap , trap);

	lli ans = dp[mouse];

	int cur = mouse;

	while(cur != trap)
	{
		ans = max(ans , dp[cur]);
		cur = pai[cur];
	}

	printf("%lld\n",ans);
}

Compilation message

mousetrap.cpp: In function 'void DFS(int, int)':
mousetrap.cpp:30:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int g = 0 ; g < grafo[i].size() ; g++)
                  ~~^~~~~~~~~~~~~~~~~
mousetrap.cpp: In function 'int main()':
mousetrap.cpp:54:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d %d",&n,&trap,&mouse);
  ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
mousetrap.cpp:58:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d",&n1,&n2);
   ~~~~~^~~~~~~~~~~~~~~~~

Subtask #1
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 24 ms 23764 KB Output is correct
2 Incorrect 23 ms 23928 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #2
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 520 ms 68052 KB Output is correct
2 Correct 472 ms 63980 KB Output is correct
3 Correct 1109 ms 69420 KB Output is correct
4 Correct 531 ms 47476 KB Output is correct
5 Correct 1127 ms 69416 KB Output is correct
6 Correct 1107 ms 69532 KB Output is correct

Subtask #3
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 24 ms 23764 KB Output is correct
2 Incorrect 23 ms 23928 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #4
0 / 35.0

# Verdict Execution time Memory Grader output
1 Correct 24 ms 23764 KB Output is correct
2 Incorrect 23 ms 23928 KB Output isn't correct
3 Halted 0 ms 0 KB -