Uva--10048（图论，floyd）

2014-09-10 17:07:20

思路：水水的floyd，只要改关键方程为：d[i][j] = min(d[i][j] , max(d[i][k] , d[k][j]))；

 1 /*************************************************************************
 2     > File Name: 10048.cpp
 3     > Author: Nature
 4     > Mail: 564374850@qq.com 
 5     > Created Time: Wed 10 Sep 2014 04:30:28 PM CST
 6 ************************************************************************/
 7 
 8 #include <cstdio>
 9 #include <cstring>
10 #include <cstdlib>
11 #include <cmath>
12 #include <vector>
13 #include <queue>
14 #include <iostream>
15 #include <algorithm>
16 using namespace std;
17 typedef long long ll;
18 const int INF = 1 << 29;
19 
20 int d[105][105];
21 int C,S,Q,Case;
22 
23 void Init(){
24     for(int i = 1; i <= C; ++i){
25         for(int j = 1; j <= C; ++j){
26             d[i][j] = INF;
27         }
28         d[i][i] = 0;
29     }
30 }
31 
32 void Floyd(){
33     for(int k = 1; k <= C; ++k)
34     for(int i = 1; i <= C; ++i)
35     for(int j = 1; j <= C; ++j) if(d[i][k] < INF && d[k][j] < INF){
36         d[i][j] = min(d[i][j],max(d[i][k],d[k][j]));
37     }
38 }
39 
40 int main(){
41     int x,y,f;
42     while(scanf("%d%d%d",&C,&S,&Q) != EOF && (C || S || Q)){
43         Init();
44         for(int i = 1; i <= S; ++i){
45             scanf("%d%d%d",&x,&y,&f);
46             d[x][y] = d[y][x] = f;
47         }
48         Floyd();
49         if(Case) puts("");
50         printf("Case #%d\n",++Case);
51         for(int i = 1; i <= Q; ++i){
52             scanf("%d%d",&x,&y);
53             if(d[x][y] >= INF) printf("no path\n");
54             else printf("%d\n",d[x][y]);
55         }
56     }
57     return 0;
58 }

 

posted @ 2014-09-10 17:08  Naturain  阅读(127)  评论(0)    收藏  举报