Submission #1481409
Source Code Expand
#include "bits/stdc++.h" using namespace std; int n; vector<int> a; vector<int> g[101010]; int root; static const int INF = 0x3f3f3f3f; int dfs(int v, int prev) { int sum = 0; int ma = -1; for (auto u : g[v]) { if (u == prev) continue; int get = dfs(u, v); ma = max(ma, get); sum += get; } if (ma == -1) return a[v]; if (sum > 2 * a[v] || sum < a[v]) throw -1; int t = 2 * a[v] - sum; if (v == root) { if (t == 0) return INF; else throw -1; } if (sum >= 2 * ma) { return t; } else { int possible = sum - ma; if (possible >= a[v] - t) return t; else throw -1; } } int main() { cin >> n; a.resize(n); for (int i = 0; i < n; i ++) cin >> a[i]; for (int i = 0; i < n - 1; i ++) { int p, q; cin >> p >> q; p --, q --; g[p].push_back(q); g[q].push_back(p); } if (n == 2) { cout << (a[0] == a[1] ? "YES" : "NO") << endl; return 0; } for (int i = 0; i < n; i ++) if (g[i].size() != 1) { root = i; break; } //cerr << root << endl; try { if (dfs(root, -1) == INF) cout << "YES" << endl; } catch (int err) { cout << "NO" << endl; return 0; } return 0; }
Submission Info
Submission Time | |
---|---|
Task | C - Cleaning |
User | KokiYmgch |
Language | C++14 (GCC 5.4.1) |
Score | 700 |
Code Size | 1683 Byte |
Status | AC |
Exec Time | 120 ms |
Memory | 12800 KB |
Judge Result
Set Name | Sample | All | ||||
---|---|---|---|---|---|---|
Score / Max Score | 0 / 0 | 700 / 700 | ||||
Status |
|
|
Set Name | Test Cases |
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Sample | sample1.txt, sample2.txt, sample3.txt |
All | sample1.txt, sample2.txt, sample3.txt, in1.txt, in10.txt, in11.txt, in12.txt, in13.txt, in14.txt, in15.txt, in16.txt, in17.txt, in18.txt, in19.txt, in2.txt, in20.txt, in21.txt, in22.txt, in23.txt, in24.txt, in25.txt, in26.txt, in27.txt, in28.txt, in29.txt, in3.txt, in30.txt, in31.txt, in32.txt, in33.txt, in34.txt, in35.txt, in36.txt, in37.txt, in38.txt, in39.txt, in4.txt, in40.txt, in41.txt, in42.txt, in43.txt, in44.txt, in45.txt, in5.txt, in6.txt, in7.txt, in8.txt, in9.txt, sample1.txt, sample2.txt, sample3.txt |
Case Name | Status | Exec Time | Memory |
---|---|---|---|
in1.txt | AC | 107 ms | 6272 KB |
in10.txt | AC | 107 ms | 6272 KB |
in11.txt | AC | 118 ms | 11520 KB |
in12.txt | AC | 120 ms | 11520 KB |
in13.txt | AC | 99 ms | 12800 KB |
in14.txt | AC | 94 ms | 11904 KB |
in15.txt | AC | 2 ms | 2560 KB |
in16.txt | AC | 2 ms | 2560 KB |
in17.txt | AC | 2 ms | 2560 KB |
in18.txt | AC | 2 ms | 2560 KB |
in19.txt | AC | 104 ms | 6272 KB |
in2.txt | AC | 105 ms | 6272 KB |
in20.txt | AC | 105 ms | 6272 KB |
in21.txt | AC | 106 ms | 6272 KB |
in22.txt | AC | 106 ms | 6272 KB |
in23.txt | AC | 109 ms | 6272 KB |
in24.txt | AC | 105 ms | 6272 KB |
in25.txt | AC | 2 ms | 2560 KB |
in26.txt | AC | 120 ms | 6272 KB |
in27.txt | AC | 114 ms | 6272 KB |
in28.txt | AC | 2 ms | 2560 KB |
in29.txt | AC | 92 ms | 6272 KB |
in3.txt | AC | 109 ms | 6272 KB |
in30.txt | AC | 2 ms | 2560 KB |
in31.txt | AC | 105 ms | 6272 KB |
in32.txt | AC | 104 ms | 6272 KB |
in33.txt | AC | 110 ms | 6272 KB |
in34.txt | AC | 107 ms | 6272 KB |
in35.txt | AC | 112 ms | 6272 KB |
in36.txt | AC | 107 ms | 6272 KB |
in37.txt | AC | 3 ms | 2688 KB |
in38.txt | AC | 106 ms | 6272 KB |
in39.txt | AC | 106 ms | 6272 KB |
in4.txt | AC | 105 ms | 6272 KB |
in40.txt | AC | 103 ms | 6272 KB |
in41.txt | AC | 111 ms | 6272 KB |
in42.txt | AC | 111 ms | 6272 KB |
in43.txt | AC | 107 ms | 6272 KB |
in44.txt | AC | 108 ms | 6272 KB |
in45.txt | AC | 120 ms | 6272 KB |
in5.txt | AC | 110 ms | 6272 KB |
in6.txt | AC | 108 ms | 6272 KB |
in7.txt | AC | 95 ms | 5888 KB |
in8.txt | AC | 27 ms | 3456 KB |
in9.txt | AC | 108 ms | 6272 KB |
sample1.txt | AC | 2 ms | 2560 KB |
sample2.txt | AC | 2 ms | 2560 KB |
sample3.txt | AC | 2 ms | 2560 KB |