poj 1364 King(差分约束)

 1 #include <iostream>
 2 #include <cstdio>
 3 #include <cstring>
 4 #include <algorithm>
 5 using namespace std;
 6 
 7 const int INF=(1<<28);
 8 int n,m,d[110];
 9 struct node
10 {
11     int u,v,w;
12 }edge[110];
13 
14 bool bellman_ford()
15 {
16     int i,j;
17     memset(d,0,sizeof(d));
18     for(i=0; i<n; i++)
19     {
20         for(j=0; j<m; j++)
21         if(d[edge[j].u]+edge[j].w<d[edge[j].v])
22         d[edge[j].v]=d[edge[j].u]+edge[j].w;
23     }
24     for(j=0; j<m; j++)
25         if(d[edge[j].u]+edge[j].w<d[edge[j].v])
26         return false;
27     return true;
28 }
29 
30 int main()
31 {
32     int a,b,c,i;
33     char s[10];
34     while(~scanf("%d",&n)&&n)
35     {
36         scanf("%d",&m);
37         for(i=0; i<m; i++)
38         {
39             scanf("%d%d%s%d",&a,&b,s,&c);
40             if(s[0]=='g')
41             {
42                 edge[i].u=a+b;
43                 edge[i].v=a-1;
44                 edge[i].w=-c-1;
45             }
46             else
47             {
48                 edge[i].u=a-1;
49                 edge[i].v=a+b;
50                 edge[i].w=c-1;
51             }
52         }
53         if(bellman_ford())
54         printf("lamentable kingdom
");
55         else
56         printf("successful conspiracy
");
57     }
58     return 0;
59 }
参考博客：http://blog.csdn.net/wangjian8006/article/details/7956848