1975: [Sdoi2010]魔法豬學院

裸題...

被double坑死了

#include <iostream> #include <cstdio> #include <cstring> #include <algorithm> #include <queue> using namespace std; typedef long long ll; #define pdi pair<double, int> #define fir first #define sec second const int N = 5005, M = 2e5+5; inline int read(){char c=getchar(); int x=0,f=1;while(c<'0'||c>'9') {if(c=='-')f=-1;c=getchar();}while(c>='0'&&c<='9') {x=x*10+c-'0';c=getchar();}return x*f; }int n, m, u, v, s, t; double en, w;namespace I {struct edge {int v, ne; double w;} e[M];int cnt, h[N];inline void ins(int u, int v, double w) {e[++cnt] = (edge){v, h[u], w}; h[u] = cnt;}priority_queue<pdi, vector<pdi>, greater<pdi> > q;int vis[N];void dij(int s, int t, double *d) {for(int i=1; i<=n; i++) d[i] = 1e15, vis[i] = 0;d[s] = 0; q.push(make_pair(0, s));while(!q.empty()) {int u = q.top().sec; q.pop();if(vis[u]) continue; vis[u] = 1;for(int i=h[u];i;i=e[i].ne) {int v = e[i].v;if(d[v] > d[u] + e[i].w) d[v] = d[u] + e[i].w, q.push(make_pair(d[v], v));}}} }struct edge {int v, ne; double w;} e[M]; int cnt, h[N]; inline void ins(int u, int v, double w) {e[++cnt] = (edge){v, h[u], w}; h[u] = cnt; } double d_t[N]; int vis[N]; priority_queue<pdi, vector<pdi>, greater<pdi> > q; void a_star(int s, int t) {I::dij(t, s, d_t);q.push(make_pair(d_t[s], s));while(!q.empty()) {int u = q.top().sec; double d = q.top().fir; q.pop();if(u == t) if((en -= d) < 0) return;vis[u]++;for(int i=h[u];i;i=e[i].ne) {int v = e[i].v;q.push(make_pair(d - d_t[u] + d_t[v] + e[i].w, v));}} } int main() {freopen("in", "r", stdin);n=read(); m=read(); scanf("%lf", &en); s=1; t=n;for(int i=1; i<=m; i++) u=read(), v=read(), scanf("%lf", &w), I::ins(v, u, w), ins(u, v, w);a_star(s, t);printf("%d\n", vis[t]); }

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