poj3615 Cow Hurdles

Posted 2020-08-14 MashiroSky

http://poj.org/problem?id=3615 (题目链接)

题意

　　给出一张有向图，求从u到v最大边最小的路径的最大边。→_→不会说话了。。

Solution

　　好久没写Floyd了，水一发。邻接表都不用打。。。

代码

// poj3615
#include<algorithm>
#include<iostream>
#include<cstdlib>
#include<cstring>
#include<cstdio>
#include<cmath>
#define LL long long
#define inf 2147483640
#define Pi acos(-1.0)
#define free(a) freopen(a".in","r",stdin),freopen(a".out","w",stdout);
using namespace std;
inline LL getint() {
	int f,x=0;char ch=getchar();
	while (ch<=‘0‘ || ch>‘9‘) {if (ch==‘-‘) f=-1;else f=1;ch=getchar();}
	while (ch>=‘0‘ && ch<=‘9‘) {x=x*10+ch-‘0‘;ch=getchar();}
	return x*f;
}

const int maxn=310;
int f[maxn][maxn],n,m,T;

int main() {
	scanf("%d%d%d",&n,&m,&T);
	for (int i=1;i<=n;i++)
		for (int j=1;j<=n;j++) if (i!=j) f[i][j]=inf;
	for (int u,v,w,i=1;i<=m;i++) {
		scanf("%d%d%d",&u,&v,&w);
		f[u][v]=w;
	}
	for (int k=1;k<=n;k++)
		for (int i=1;i<=n;i++)
			for (int j=1;j<=n;j++)
				f[i][j]=min(f[i][j],max(f[i][k],f[k][j]));
	for (int x,y,i=1;i<=T;i++) {
		scanf("%d%d",&x,&y);
		if (f[x][y]==inf) puts("-1");
		else printf("%d\n",f[x][y]);
	}
	return 0;
}