OJ-Problems-Source/HDOJ/5168_autoAC.cpp

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#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cmath>
#include <cstring>
#include <vector>
#define LL __int64
using namespace std;
const LL INF=(LL)0x3f3f3f3f*0x3f3f3f3f;
const int N=100010;
const int M=200020;
struct TEdge{
int u,v,w;
bool operator<(const TEdge& a)const {
if(w<a.w) return true;
return false;
}
}Cedge[M];
int tot;
struct Point{
int lw;
LL alw;
Point(int c,LL e){lw=c; alw=e;}
};
vector<Point>point[N];
int n,m,k;
void addedge(int u,int v,int w){
Cedge[tot].u=u;
Cedge[tot].v=v;
Cedge[tot].w=w;
tot++;
}
void Push_into(int p,Point t){
point[p].push_back(t);
}
bool cmp(Point a,Point b){
if(a.lw==b.lw) return a.alw>b.alw;
return a.lw<b.lw;
}
int main(){
int T,u,v,w,sz;
scanf("%d",&T);
while(T--){
scanf("%d%d%d",&n,&m,&k);
tot=0;
for(int i=1;i<=n;i++){
point[i].clear();
}
for(int i=1;i<=m;i++){
scanf("%d%d%d",&u,&v,&w);
addedge(u,v,w);
}
sort(Cedge,Cedge+tot);
for(int i=0;i<tot;i++){
u=Cedge[i].u;
v=Cedge[i].v;
if(u==1){
if(point[v].empty()){
Push_into(v,Point(Cedge[i].w,Cedge[i].w));
}
else{
if(point[v][point[v].size()-1].alw>Cedge[i].w){
Push_into(v,Point(Cedge[i].w,Cedge[i].w));
}
}
continue;
}
if(point[u].empty()) continue;
else {
int p=upper_bound(point[u].begin(),point[u].end(),Point(Cedge[i].w-k,-INF),cmp)-point[u].begin();
if(p==0) continue;
else if(p>0 && p<point[u].size()) --p;
else if(point[u][point[u].size()-1].lw<=Cedge[i].w-k) p=point[u].size()-1;
else continue;
if(point[v].empty())
Push_into(v,Point(Cedge[i].w,point[u][p].alw+(LL)Cedge[i].w));
else if(point[v][point[v].size()-1].alw>point[u][p].alw+(LL)Cedge[i].w)
Push_into(v,Point(Cedge[i].w,point[u][p].alw+(LL)Cedge[i].w));
}
}
if(point[n].empty())
printf("-1\n");
else printf("%I64d\n",point[n][point[n].size()-1].alw);
}
return 0;
}