結果
| 問題 |
No.1473 おでぶなおばけさん
|
| コンテスト | |
| ユーザー |
|
| 提出日時 | 2022-05-15 20:04:54 |
| 言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
| 結果 |
AC
|
| 実行時間 | 1,980 ms / 2,000 ms |
| コード長 | 3,979 bytes |
| コンパイル時間 | 4,786 ms |
| コンパイル使用メモリ | 270,900 KB |
| 最終ジャッジ日時 | 2025-01-29 08:20:16 |
|
ジャッジサーバーID (参考情報) |
judge4 / judge2 |
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| ファイルパターン | 結果 |
|---|---|
| sample | AC * 2 |
| other | AC * 47 |
ソースコード
#pragma region Macros
#include <bits/stdc++.h>
#if defined(LOCAL) || defined(ONLINE_JUDGE) || defined(_DEBUG)
#include <atcoder/all>
#endif
using namespace std;
#define REP(i, n) for(int i=0, i##_len=(n); i<i##_len; ++i)
#define REPR(i, n) for(int i=(n); i>=0; --i)
#define FOR(i, n, m) for(int i=(m), i##_len=(n); i<i##_len; ++i)
#define EACH(i, v) for(const auto& i : v)
#define ALL(x) (x).begin(),(x).end()
#define ALLR(x) (x).rbegin(),(x).rend()
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }
template<class T>using vec = vector<T>;
template<class T, class U>using umap = unordered_map<T, U>;
template<class T>using uset = unordered_set<T>;
using ll = long long;
using ld = long double;
using P = pair<ll, ll>;
//using T = tuple<ll, ll, ll>;
using vl = vec<ll>;
#define fi first
#define se second
#define el endl
constexpr ll INF = numeric_limits<ll>::max()/2-1;
#pragma endregion
#pragma region IOMacros
template<class T>
istream &operator>>(istream &stream, vec<T>& o){REP(i, o.size())stream >> o[i];return stream;}
template<class T>
ostream &operator<<(ostream &stream, vec<T>& objs){REP(i, objs.size())stream << objs[i] << " ";stream << el;return stream;}
#define I(T, ...) ;T __VA_ARGS__;__i(__VA_ARGS__);
void __i() {}
template<class T, class... Ts> void __i(T&& o, Ts&&... args){cin >> o;__i(forward<Ts>(args)...);}
void O() {cout << el;}
template<class T, class... Ts> void O(T&& o, Ts&&... args){cerr << o << " ";O(forward<Ts>(args)...);}
#pragma endregion
void Main();
int main(){
std::cin.tie(nullptr);
std::cout << std::fixed << std::setprecision(15);
Main();
return 0;
}
#pragma region graph
struct edge{
ll from, to, cost;
bool operator<(const edge& r) const{return cost<r.cost;}
bool operator>(const edge& r) const{return cost>r.cost;}
};
struct graph{
ll V;
vector<vector<edge> > G;
graph(ll n){
init(n);
}
void init(ll n){
V = n;
G.resize(V);
}
// 無向グラフ
void add_edge(ll s, ll t, ll cost = 1){
add_diedge(s, t, cost);
add_diedge(t, s, cost);
}
// 有向グラフ
void add_diedge(ll s, ll t, ll cost = 1){
if(s < 0 || t < 0 || s >= V || t >= V) return;
G[s].push_back({s, t, cost});
}
auto pos2d(ll height, ll width){
return [height, width](ll y, ll x){
return
(y < 0 || y >= height || x < 0 || x >= width)
? -1
: y*width + x;
};
}
};
#pragma endregion
// O(V+E)
umap<ll, ll> BFS(const graph& g, ll s, ll limit = INF){
vector<ll> d(g.V, INF);
umap<ll, ll> ret;
d[s] = 0;
queue<P> que;
que.push({0, s});
ret[s] = 0;
while(!que.empty()){
auto [c, v] = que.front(); que.pop();
if(d[v]<c) continue;
for(auto e : g.G[v]){
ll l = d[v]+e.cost;
if(d[e.to]>l && limit>=l){
d[e.to] = l;
que.push({d[e.to],e.to});
ret[e.to] = d[e.to];
}
}
}
return ret;
}
// x∈[l, r] | f(x) = true となる最大のxを返す
template <class Func>
ll binarySearch(ll l, ll r, Func f){
while(l < r){
const ll m = (l+r+1)/2;
if(f(m)) l = m;
else r = m-1;
}
return l;
}
void Main(){
I(ll, N, M);
vec<tuple<ll, ll, ll>> A(M);
REP(i, M){
I(ll, S, T, D);
S--;T--;
A[i] = {S, T, D};
}
ll t = 0;
ll x = binarySearch(0, 1e9, [&](ll m){
graph g(N);
REP(i, M){
auto [S, T, D] = A[i];
if(m > D) continue;
g.add_edge(S, T);
}
auto d = BFS(g, 0);
if(d.find(N-1) != d.end()){
t = d[N-1];
return true;
}else{
return false;
}
});
cout << x << " " << t << el;
}