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Submission #25733

# Submission time Handle Problem Language Result Execution time Memory
25733 2017-06-23T21:18:26 Z nibnalin Network (BOI15_net) C++14
0 / 100
 0 ms 3972 KB 
#include <iostream>
#include <cstdio>
#include <vector>
using namespace std;

const int maxn = int(5e5)+5;

int deg[maxn];

int main(void)
{
	int n, u, v;
	scanf("%d", &n);
	for(int i = 1;i < n;i++)
	{
		scanf("%d%d", &u, &v);
		u--, v--;
		deg[u]++, deg[v]++;
	}

	vector<int> leafs;
	for(int i = 0;i < n;i++)
	{
		if(deg[i] == 1)
		{
			leafs.push_back(i);
		}
	}

	printf("%d\n", int(leafs.size())/2+int(leafs.size())%2);
	for(int i = 0;i < int(leafs.size())-1;i += 2)
	{
		printf("%d %d\n", leafs[i]+1, leafs[i+1]+1);
	}

	if(int(leafs.size()%2)) printf("%d %d\n", leafs[int(leafs.size())-2]+1, leafs[int(leafs.size())-1]+1);
}

Compilation message

net.cpp: In function 'int main()':
net.cpp:13:17: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &n);
                 ^
net.cpp:16:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d", &u, &v);
                        ^

Subtask #1
0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 3972 KB Output is correct
2 Correct 0 ms 3972 KB Output is correct
3 Correct 0 ms 3972 KB Output is correct
4 Correct 0 ms 3972 KB Output is correct
5 Correct 0 ms 3972 KB Output is correct
6 Correct 0 ms 3972 KB Output is correct
7 Correct 0 ms 3972 KB Output is correct
8 Correct 0 ms 3972 KB Output is correct
9 Correct 0 ms 3972 KB Output is correct
10 Incorrect 0 ms 3972 KB Breaking single line is causing network to disconnect.
11 Halted 0 ms 0 KB -

Subtask #2
0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 3972 KB Output is correct
2 Correct 0 ms 3972 KB Output is correct
3 Correct 0 ms 3972 KB Output is correct
4 Correct 0 ms 3972 KB Output is correct
5 Correct 0 ms 3972 KB Output is correct
6 Correct 0 ms 3972 KB Output is correct
7 Correct 0 ms 3972 KB Output is correct
8 Correct 0 ms 3972 KB Output is correct
9 Correct 0 ms 3972 KB Output is correct
10 Incorrect 0 ms 3972 KB Breaking single line is causing network to disconnect.
11 Halted 0 ms 0 KB -

Subtask #3
0 / 37.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 3972 KB Output is correct
2 Correct 0 ms 3972 KB Output is correct
3 Correct 0 ms 3972 KB Output is correct
4 Correct 0 ms 3972 KB Output is correct
5 Correct 0 ms 3972 KB Output is correct
6 Correct 0 ms 3972 KB Output is correct
7 Correct 0 ms 3972 KB Output is correct
8 Correct 0 ms 3972 KB Output is correct
9 Correct 0 ms 3972 KB Output is correct
10 Incorrect 0 ms 3972 KB Breaking single line is causing network to disconnect.
11 Halted 0 ms 0 KB -