hdu1599 find the mincost route

题目链接

floyd找最小环

很好理解

 1 #include<algorithm>
 2 #include<iostream>
 3 #include<cstdlib>
 4 #include<cstring>
 5 #include<cstdio>
 6 #include<string>
 7 #include<cmath>
 8 #include<ctime>
 9 #include<queue>
10 #include<stack>
11 #include<map>
12 #include<set>
13 #define rre(i,r,l) for(int i=(r);i>=(l);i--)
14 #define re(i,l,r) for(int i=(l);i<=(r);i++)
15 #define Clear(a,b) memset(a,b,sizeof(a))
16 #define inout(x) printf("%d",(x))
17 #define douin(x) scanf("%lf",&x)
18 #define strin(x) scanf("%s",(x))
19 #define LLin(x) scanf("%lld",&x)
20 #define op operator
21 #define CSC main
22 typedef unsigned long long ULL;
23 typedef const int cint;
24 typedef long long LL;
25 using namespace std;
26 cint inf=214748364;
27 void inin(int &ret)
28 {
29     ret=0;int f=0;char ch=getchar();
30     while(ch<'0'||ch>'9'){if(ch=='-')f=1;ch=getchar();}
31     while(ch>='0'&&ch<='9')ret*=10,ret+=ch-'0',ch=getchar();
32     ret=f?-ret:ret;
33 }
34 int n,m,t,dis[111][111],mp[111][111];
35 int floyd()
36 {
37     int ret=inf;
38     re(k,1,n)
39     {
40         re(i,1,n)if(i!=k)
41             re(j,1,n)if(j!=k&&j!=i)
42                 if(dis[i][j]<inf&&mp[i][k]!=inf&&mp[k][j]!=inf)
43                     ret=min(ret,mp[i][k]+mp[k][j]+dis[i][j]);
44         re(i,1,n)
45             re(j,1,n)
46                 dis[i][j]=min(dis[i][j],dis[i][k]+dis[k][j]);
47     }
48     return ret;
49 }
50 int main()
51 {
52     while(scanf("%d%d",&n,&m)!=EOF)
53     {
54         re(i,1,n)re(j,1,m)dis[i][j]=mp[i][j]=inf;
55         re(i,1,m)
56         {
57             int q,w,e;inin(q),inin(w),inin(e);
58             dis[q][w]=dis[w][q]=mp[q][w]=mp[w][q]=min(dis[q][w],e);
59         }
60         int ans=floyd();
61         if(ans==inf)printf("It's impossible.\n");
62         else printf("%d\n",ans);
63     }
64      return 0;
65 }

 

posted @ 2016-03-16 20:58  HugeGun  阅读(124)  评论(0编辑  收藏  举报