# | Submission time | Handle | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
113185 | 2019-05-24T08:07:17 Z | davitmarg | Network (BOI15_net) | C++17 | 4 ms | 2688 KB |
/*DavitMarg*/ #include <iostream> #include <algorithm> #include <cmath> #include <vector> #include <string> #include <cstring> #include <map> #include <set> #include <queue> #include <iomanip> #include <bitset> #include <stack> #include <cassert> #include <iterator> #include <ctype.h> #include <fstream> #define mod 1000000007ll #define LL long long #define LD long double #define MP make_pair #define PB push_back #define all(v) v.begin (),v.end() using namespace std; int n,used[100005],start; vector<int> g[100005],a,b; vector<pair<int, int>> ans; void dfs(int v) { used[v] = 1; if (g[v].size() == 1) { if(a.empty()) b.PB(v); else { ans.PB(MP(a.back(), v)); a.pop_back(); } } for (int i = 0; i < g[v].size(); i++) { int to = g[v][i]; if (used[to]) continue; dfs(to); if (v == start) { while (!b.empty()) { a.PB(b.back()); b.pop_back(); } } } } int main() { cin >> n; if (n == 0) { printf("0\n"); return 0; } else if (n == 2) { printf("1\n"); printf("1 2\n"); return 0; } for (int i = 1; i < n; i++) { int a, b; scanf("%d%d", &a, &b); g[a].PB(b); g[b].PB(a); } for(int i=1;i<=n;i++) if (g[i].size() != 1) { start = i; break; } dfs(start); if (!a.empty()) if (a[0] == 1) ans.PB(MP(1, 2)); else ans.PB(MP(1, a[0])); printf("%d\n",(int)ans.size()); for (int i = 0; i < ans.size(); i++) printf("%d %d\n", ans[i].first, ans[i].second); return 0; } /* */
Compilation message
# | Verdict | Execution time | Memory | Grader output |
---|---|---|---|---|
1 | Correct | 4 ms | 2688 KB | Output is correct |
2 | Incorrect | 3 ms | 2688 KB | Breaking single line is causing network to disconnect. |
3 | Halted | 0 ms | 0 KB | - |
# | Verdict | Execution time | Memory | Grader output |
---|---|---|---|---|
1 | Correct | 4 ms | 2688 KB | Output is correct |
2 | Incorrect | 3 ms | 2688 KB | Breaking single line is causing network to disconnect. |
3 | Halted | 0 ms | 0 KB | - |
# | Verdict | Execution time | Memory | Grader output |
---|---|---|---|---|
1 | Correct | 4 ms | 2688 KB | Output is correct |
2 | Incorrect | 3 ms | 2688 KB | Breaking single line is causing network to disconnect. |
3 | Halted | 0 ms | 0 KB | - |