POJ 2253 Frogger

题目大意:给一个图,求给出的两个节点之间,所有路径中权值最大的最小值(就是取出每一条路径里的权值最大值,然后答案就是这些最大值的最小值,有些拗口,注意一下)

分析:赤裸裸的Floyd。O(n^3)复杂度,贴出代码:

 1 #include<stdio.h>
 2 #include<cmath>
 3 #include<cstring>
 4 #define Max 210
 5 int n,k=0;
 6 struct Point
 7 {
 8     double x,y;
 9 }point[Max];
10 double map[Max][Max];
11 double juli(Point a,Point b)
12 {
13     double x,y;
14     x=(a.x-b.x)*(a.x-b.x);
15     y=(a.y-b.y)*(a.y-b.y);
16     return sqrt(x+y);
17 }
18 void init()
19 {
20     int i,j;
21     for(i=1;i<=n;i++)
22         scanf("%lf%lf",&point[i].x,&point[i].y);
23     for(i=1;i<n;i++)
24     for(j=i+1;j<=n;j++){
25         map[i][j]=map[j][i]=juli(point[i],point[j]);
26     }
27 }
28 void solve()
29 {
30     int k,i,j;
31     for(k=1;k<=n;k++)
32     for(i=1;i<=n;i++)
33     for(j=i+1;j<=n;j++)
34     if(map[i][k]<map[i][j] && map[k][j]<map[i][j]){
35             if(map[i][k]<map[k][j]) map[j][i]=map[i][j]=map[k][j];
36             else                    map[j][i]=map[i][j]=map[i][k];
37 
38     }
39 }
40 void outit()
41 {
42     printf("Scenario #%d
",++k);
43     printf("Frog Distance = %.3lf

",map[1][2]);
44 }
45 int main()
46 {
47     while(scanf("%d",&n) && n){
48         init();
49         solve();
50         outit();
51     }
52     return 0;
53 }
View Code
原文地址:https://www.cnblogs.com/bokezhilu/p/3608714.html