oj.uz

답안 #23240

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
23240 2017-05-05T12:27:16 Z jjwdi0 Network (BOI15_net) C++11
0 / 100
 6 ms 14224 KB 
#include <bits/stdc++.h>
using namespace std;

int N;
vector<int> v[500005], ans;
bool leaf[500005];

void dfs(int x, int p) {
    for(int it : v[x]) {
        if(it == p) continue;
        dfs(it, x);
    }
    if(v[x].size() == 1) leaf[x] = 1;
}

int main() {
    scanf("%d", &N);
    for(int i=1, x, y; i<N; i++) {
        scanf("%d %d", &x, &y);
        v[x].push_back(y);
        v[y].push_back(x);
    }
    dfs(1, 0);
    for(int i=1; i<=N; i++) if(leaf[i]) ans.push_back(i);
    if((int)ans.size() % 2 == 1) ans.push_back(ans[0]);
    printf("%d\n", (int)ans.size() / 2);
    for(int i=0; i<ans.size(); i+=2) printf("%d %d\n", ans[i], ans[i+1]);
}

Compilation message

net.cpp: In function 'int main()':
net.cpp:27:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0; i<ans.size(); i+=2) printf("%d %d\n", ans[i], ans[i+1]);
                   ^
net.cpp:17:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &N);
                    ^
net.cpp:19:31: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d %d", &x, &y);
                               ^

Subtask #1
0 / 18.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 14224 KB Output is correct
2 Correct 0 ms 14224 KB Output is correct
3 Correct 6 ms 14224 KB Output is correct
4 Correct 0 ms 14224 KB Output is correct
5 Correct 6 ms 14224 KB Output is correct
6 Correct 0 ms 14224 KB Output is correct
7 Correct 6 ms 14224 KB Output is correct
8 Correct 3 ms 14224 KB Output is correct
9 Correct 0 ms 14224 KB Output is correct
10 Incorrect 6 ms 14224 KB Breaking single line is causing network to disconnect.
11 Halted 0 ms 0 KB -

Subtask #2
0 / 45.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 14224 KB Output is correct
2 Correct 0 ms 14224 KB Output is correct
3 Correct 6 ms 14224 KB Output is correct
4 Correct 0 ms 14224 KB Output is correct
5 Correct 6 ms 14224 KB Output is correct
6 Correct 0 ms 14224 KB Output is correct
7 Correct 6 ms 14224 KB Output is correct
8 Correct 3 ms 14224 KB Output is correct
9 Correct 0 ms 14224 KB Output is correct
10 Incorrect 6 ms 14224 KB Breaking single line is causing network to disconnect.
11 Halted 0 ms 0 KB -

Subtask #3
0 / 37.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 14224 KB Output is correct
2 Correct 0 ms 14224 KB Output is correct
3 Correct 6 ms 14224 KB Output is correct
4 Correct 0 ms 14224 KB Output is correct
5 Correct 6 ms 14224 KB Output is correct
6 Correct 0 ms 14224 KB Output is correct
7 Correct 6 ms 14224 KB Output is correct
8 Correct 3 ms 14224 KB Output is correct
9 Correct 0 ms 14224 KB Output is correct
10 Incorrect 6 ms 14224 KB Breaking single line is causing network to disconnect.
11 Halted 0 ms 0 KB -