結果
問題 | No.1599 Hikyaku |
ユーザー |
👑 ![]() |
提出日時 | 2021-07-10 16:09:42 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 2,276 ms / 7,500 ms |
コード長 | 2,959 bytes |
コンパイル時間 | 1,277 ms |
コンパイル使用メモリ | 88,632 KB |
最終ジャッジ日時 | 2025-01-23 00:21:34 |
ジャッジサーバーID (参考情報) |
judge5 / judge4 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 4 |
other | AC * 49 |
ソースコード
#include <iostream> #include <vector> #include <queue> using namespace std; using ll = long long; using ull = unsigned long long; #define rep(i,n) for(int i=0; i<(n); i++) template<class T> using nega_queue = priority_queue<T,vector<T>,greater<T>>; const int INF = 1001001001; const int W = 600; const int H = 600; const int NV = W * H; // number of vertices const int maxV = 7; struct Start{ int id,v; }; int pos2id(int y,int x){ return y * W + x; } int X,Y; int N; vector<Start> hikyaku; double dt[maxV]; double V[maxV]; double T[maxV][NV]; vector<int> E[NV]; double D[maxV][NV]; int main(){ cin >> X >> Y; X--; Y--; cin >> N; rep(y,H) rep(x,W-1) E[pos2id(y,x)].push_back(pos2id(y,x+1)); rep(y,H) rep(x,W-1) E[pos2id(y,x+1)].push_back(pos2id(y,x)); rep(y,H-1) rep(x,W) E[pos2id(y,x)].push_back(pos2id(y+1,x)); rep(y,H-1) rep(x,W) E[pos2id(y+1,x)].push_back(pos2id(y,x)); hikyaku.resize(N); rep(i,N){ int x,y,v; cin >> x >> y >> v; x--; y--; v--; hikyaku[i] = { pos2id(y,x),v }; } rep(v,maxV) V[v] = 1+v; rep(v,maxV) dt[v] = 1000.0 / (1+v); rep(v,maxV) rep(i,NV) T[v][i] = INF; { vector<vector<int>> I(maxV); for(auto a : hikyaku){ I[a.v].push_back(a.id); T[a.v][a.id] = 0; } rep(v,maxV){ rep(i,I[v].size()){ int p = I[v][i]; for(int e : E[p]) if(T[v][e] >= INF - 1.0){ T[v][e] = T[v][p] + dt[v]; I[v].push_back(e); } } } } rep(v,maxV) rep(i,NV) D[v][i] = INF; nega_queue<pair<double,pair<int,int>>> Q; D[hikyaku[0].v][hikyaku[0].id] = 0.0; Q.push(make_pair(0.0,make_pair(hikyaku[0].v,hikyaku[0].id))); while(Q.size()){ double d = Q.top().first; int v = Q.top().second.first; int p = Q.top().second.second; Q.pop(); if(D[v][p] != d) continue; for(int nxv=v+1; nxv<maxV; nxv++) if(D[nxv][p] > max(T[nxv][p],d)){ D[nxv][p] = max(T[nxv][p],d); Q.push(make_pair(D[nxv][p],make_pair(nxv,p))); } for(int e : E[p]){ if(D[v][e] > d + dt[v]){ D[v][e] = d + dt[v]; Q.push(make_pair(D[v][e],make_pair(v,e))); } double nxd = dt[v]; int pv = v; for(int nxv=v+1; nxv<maxV; nxv++){ double t0 = d + nxd - max(d - dt[nxv], T[nxv][e]); //cout << "p = " << p << ", e = " << e << ", pv = " << pv << ", nxv = " << nxv << ", t0 = " << t0 << endl; if(t0 < 0) continue; t0 = min(t0,dt[pv]+dt[nxv]); double t = nxd - t0 * (V[nxv] - V[pv]) / (V[nxv] + V[pv]); nxd = t; pv = nxv; if(D[nxv][e] <= d+nxd) continue; D[nxv][e] = d+nxd; Q.push(make_pair(d+nxd,make_pair(nxv,e))); } } } double ans = INF; rep(v,maxV) ans = min(ans,D[v][pos2id(Y,X)]); cout.precision(10); cout << fixed; cout << ans << endl; return 0; } struct ios_do_not_sync{ ios_do_not_sync(){ ios::sync_with_stdio(false); cin.tie(nullptr); } } ios_do_not_sync_inst;