delete pics to save space

7.3662.cpp

@@ -0,0 +1,55 @@
+#include<cstdio>
+#include<cstring>
+#include<algorithm>
+#include<vector>
+#include<deque>
+using namespace std;
+const int maxn=1005;
+const int maxm=10005;
+int n,m,Q,dis[maxn],vis[maxn];
+struct Edge { int v,w; Edge *nxt; };
+Edge mem[maxm*2],*G[maxn],*ecnt=mem;
+inline void AddEdge(int u,int v,int w) { ecnt->v=v; ecnt->w=w; ecnt->nxt=G[u]; G[u]=ecnt++; }
+int cal(int cost)
+{
+	memset(dis,0x3f,sizeof(dis)); memset(vis,0,sizeof(vis));
+	dis[1]=0;
+	deque<int> Q; Q.push_back(1);
+	while(Q.size())
+	{
+		int u=Q.front(); Q.pop_front();
+		if(vis[u]) continue;
+		vis[u]=1;
+		for(Edge *it=G[u];it;it=it->nxt)
+		{
+			int v=it->v,w=(it->w>cost?1:0);
+			dis[v]=min(dis[v],dis[u]+w);
+			if(w) Q.push_back(v);
+			else Q.push_front(v);
+		}
+	}
+	return dis[n];
+}
+int main()
+{
+	#ifdef local
+	freopen("pro.in","r",stdin);
+	#endif
+	scanf("%d%d%d",&n,&m,&Q);
+	int L=0,R=0,M,res;
+	for(int i=0;i<m;i++)
+	{
+		int u,v,w; scanf("%d%d%d",&u,&v,&w);
+		AddEdge(u,v,w); AddEdge(v,u,w);
+		R=max(R,w);
+	}
+	res=R+1; int oo=R+1;
+	while(L<=R)
+	{
+		M=(L+R)>>1;
+		if(cal(M)<=Q) res=M,R=M-1;
+		else L=M+1;
+	}
+	printf("%d\n",res==oo?-1:res);
+	return 0;
+}