結果
問題 | No.2565 はじめてのおつかい |
ユーザー |
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提出日時 | 2023-12-02 16:49:27 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 101 ms / 2,000 ms |
コード長 | 4,465 bytes |
コンパイル時間 | 4,614 ms |
コンパイル使用メモリ | 262,744 KB |
最終ジャッジ日時 | 2025-02-18 05:41:23 |
ジャッジサーバーID (参考情報) |
judge2 / judge2 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 3 |
other | AC * 50 |
ソースコード
// コンパイルはctrl + shift + B#include <bits/stdc++.h>#include <atcoder/all>using namespace std;using namespace atcoder;#define ll long long#define all(x) (x).begin(), (x).end()#define yes "Yes"#define no "No"// 最大公約数 O(log(N))template<typename T>T gcd(T a, T b) {if (b == 0) return a;else return gcd(b, a % b);}// 素数判定 O(sqrt(N))bool is_prime(ll n) {for (ll i = 2; i*i <= n; i++) {if (n % i == 0) return false;}return true;}//n以下の素数求めマシーン O(Nloglog(N))vector<ll> getprime(ll n) {vector<ll> ans;vector<bool> isprime(n + 1, true);//0, 1はダメisprime[0] = false; isprime[1] = false;//やるfor (int i = 2; i <= n; i++) {if (!isprime[i]) continue;ans.push_back(i);for (int j = 2 * i; j <= n; j += i) {//i以外のiの倍数をキャンセルisprime[j] = false;}}return ans;}// nを素因数分解 O(sqrt(N))vector<pair<ll, ll>> prime_factorize(ll n) {vector<pair<ll, ll>> ans;for (ll i = 2; i*i <= n; i++) {if (n % i != 0) continue;ll e = 0;while (n % i == 0) {e++;n /= i;}ans.push_back({i, e});}if (n != 1) ans.push_back({n, 1});return ans;}// 各n以下の最小の素因数 O(NlogN)vector<ll> smallest_prime(ll n) {vector<ll> spf(n+1);for (ll i = 0; i <= n; i++) spf[i] = i; //初期化for (ll i = 2; i+i <= n; i++) {if (spf[i] == i) {for (ll j = i*i; j <= n; j += i) {if (spf[j] == j) spf[j] = i;}}}return spf;}// 以下、コードを記すのである。// using mint = modint998244353;using mint = modint1000000007;int main() {int n, m; cin >> n >> m;vector<vector<int>> e(n);for (int i = 0; i < m; i++) {int u, v; cin >> u >> v;u--; v--;e[u].push_back(v);}ll INF = 1e18;vector<ll> iki(n, INF);iki[0] = 0;queue<int> q;q.push(0);vector<bool> seen(n);seen[0] = true;while (q.size()) {int u = q.front(); q.pop();for (auto v : e[u]) {if (seen[v]) continue;seen[v] = true;iki[v] = iki[u] + 1;q.push(v);}}bool a = seen[n-2];bool b = seen[n-1];int ans = -1;if (a) {bool f = true;int now = iki[n-2];q.push(n-2);vector<bool> seen(n);seen[n-2] = true;vector<int> d(n);while (q.size()) {int u = q.front(); q.pop();for (auto v : e[u]) {if (seen[v]) continue;seen[v] = true;d[v] = d[u] + 1;q.push(v);}}if (seen[n-1]) now += d[n-1];else f = false;q.push(n-1);vector<bool> seen1(n);seen[n-1] = true;vector<int> d1(n);while (q.size()) {int u = q.front(); q.pop();for (auto v : e[u]) {if (seen1[v]) continue;seen1[v] = true;d1[v] = d1[u] + 1;q.push(v);}}if (seen1[0]) now += d1[0];else f = false;if (f) ans = now;}if (b) {bool f = true;int now = iki[n-1];q.push(n-1);vector<bool> seen(n);seen[n-1] = true;vector<int> di(n);while (q.size()) {int u = q.front(); q.pop();for (auto v : e[u]) {if (seen[v]) continue;seen[v] = true;di[v] = di[u] + 1;q.push(v);}}if (seen[n-2]) now += di[n-2];else f = false;q.push(n-2);vector<bool> seen1(n);seen[n-2] = true;vector<int> di1(n);while (q.size()) {int u = q.front(); q.pop();for (auto v : e[u]) {if (seen1[v]) continue;seen1[v] = true;di1[v] = di1[u] + 1;q.push(v);}}if (seen1[0]) now += di1[0];else f = false;if (f) {if (ans < 0) ans = now;else ans = min(ans, now);}}cout << ans << endl;}