bzoj1202 [HNOI2005]狡猾的商人

 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 void inin(int &ret)
27 {
28     ret=0;int f=0;char ch=getchar();
29     while(ch<‘0‘||ch>‘9‘){if(ch==‘-‘)f=1;ch=getchar();}
30     while(ch>=‘0‘&&ch<=‘9‘)ret*=10,ret+=ch-‘0‘,ch=getchar();
31     ret=f?-ret:ret;
32 }
33 int t,v[111],n,m;
34 int fa[111];
35 int find(int x)
36 {
37     if(fa[x]==x)return x;
38     int t=find(fa[x]);
39     v[x]+=v[fa[x]];
40     fa[x]=t;
41     return t;
42 }
43 bool pd(int x,int y,int ww)
44 {
45     int q=find(x),w=find(y);
46     if(q==w)return v[y]-v[x]==ww;
47     fa[q]=w;
48     v[q]=v[y]-v[x]-ww;
49     return 1;
50 }
51 int CSC()
52 {
53     inin(t);
54     while(t--)
55     {
56         inin(n),inin(m);Clear(v,0);
57         int flag=0;
58         re(i,0,n)fa[i]=i;
59         re(i,1,m)
60         {
61             int q,w,e;
62             inin(q),inin(w),inin(e);
63             if(!pd(q-1,w,e))flag=1;
64         }
65         if(flag)cout<<"false\n";
66         else cout<<"true\n";
67     }
68     return 0;
69 }