제출 #23242

#제출 시각아이디문제언어결과실행 시간메모리
23242jjwdi0Network (BOI15_net)C++11
0 / 100
6 ms14224 KiB
#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((int)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); } for(int i=1; i<=N; i++) if(v[i].size() > 1) { dfs(i, 0); break; } for(int i=1; i<=N; i++) if(leaf[i]) ans.push_back(i); printf("%d\n", (int)(ans.size() + 1) / 2); for(int i=0; i<(ans.size() + 1) / 2; i++) printf("%d %d\n", ans[i], ans[i+ans.size()/2]); }

컴파일 시 표준 에러 (stderr) 메시지

net.cpp: In function 'int main()':
net.cpp:26:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0; i<(ans.size() + 1) / 2; i++) printf("%d %d\n", ans[i], ans[i+ans.size()/2]);
                   ^
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);
                               ^
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...