結果
問題 | No.1507 Road Blocked |
ユーザー |
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提出日時 | 2021-05-20 21:18:46 |
言語 | C++14 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 50 ms / 2,000 ms |
コード長 | 2,739 bytes |
コンパイル時間 | 3,282 ms |
コンパイル使用メモリ | 163,108 KB |
実行使用メモリ | 16,148 KB |
最終ジャッジ日時 | 2024-10-10 07:19:44 |
合計ジャッジ時間 | 5,926 ms |
ジャッジサーバーID (参考情報) |
judge2 / judge3 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 3 |
other | AC * 30 |
コンパイルメッセージ
main.cpp: In function 'int main()': main.cpp:106:10: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17' [-Wc++17-extensions] 106 | auto [a, b] = edges[i]; | ^
ソースコード
#include <iostream>#include <iomanip>#include <cstdio>#include <queue>#include <cstring>#include <vector>#include <map>#include <algorithm>#include <cctype>#include <cmath>#include <bitset>#include <set>#include <deque>#include <stack>#include <atcoder/all>#include <array>using namespace std;#define rep(i,n) for(int i = 0; i < (n); ++i)#define rrep(i,n) for(int i = 1; i <= (n); ++i)#define drep(i,n) for(int i = (n)-1; i >= 0; --i)#define srep(i,s,t) for (int i = s; i < (t); ++i)#define dsrep(i,t,s) for(int i = (t)-1; i >= (s); --i)#define rng(a) a.begin(),a.end()#define rrng(a) a.rbegin(),a.rend()#define isin(x,l,r) ((l) <= (x) && (x) < (r))int dx4[4]={1,0,-1,0};int dy4[4]={0,-1,0,1};using ll = long long;using uint = unsigned;using ull = unsigned long long;using P = pair<int,int>;const ll LINF = 1001002003004005006ll;const int INF = 1001001001;const ll mod = 998244353;// const ll mod = 1e9 + 7;////////////////////////////////////////////int n;vector<int> g[100005];struct mint {ll x; // typedef long long ll;mint(ll x=0):x((x%mod+mod)%mod){}mint operator-() const { return mint(-x);}mint& operator+=(const mint a) {if ((x += a.x) >= mod) x -= mod;return *this;}mint& operator-=(const mint a) {if ((x += mod-a.x) >= mod) x -= mod;return *this;}mint& operator*=(const mint a) { (x *= a.x) %= mod; return *this;}mint operator+(const mint a) const { return mint(*this) += a;}mint operator-(const mint a) const { return mint(*this) -= a;}mint operator*(const mint a) const { return mint(*this) *= a;}mint pow(ll t) const {if (!t) return 1;mint a = pow(t>>1);a *= a;if (t&1) a *= *this;return a;}// for prime modmint inv() const { return pow(mod-2);}mint& operator/=(const mint a) { return *this *= a.inv();}mint operator/(const mint a) const { return mint(*this) /= a;}};istream& operator>>(istream& is, mint& a) { return is >> a.x;}ostream& operator<<(ostream& os, const mint& a) { return os << a.x;}int dfs(int s, vector<int> &dept) {int sum = 1;dept[s] = 0;for(auto x : g[s]) {if(dept[x] != -1) continue;sum += dfs(x, dept);}return dept[s] = sum;}int main() {cin.tie(0);ios::sync_with_stdio(false);cin >> n;vector<P> edges;rep(i, n - 1) {int a, b;cin >> a >> b;a--; b--;g[a].push_back(b);g[b].push_back(a);edges.push_back(P(a, b));}vector<int> dept(n, -1);dfs(0, dept);mint q = n; q *= n - 1; q *= n - 1;mint p = 0;rep(i, n - 1) {auto [a, b] = edges[i];ll x = min(dept[a], dept[b]);p += x * (x - 1);p += (ll)(n - x) * (ll)(n - x - 1);}cout << (p / q) << endl;}