BZOJ1202(HNOI2005)[狡猾的商人]--并查集

【链接】
bzoj1202

【解题报告】

并查集维护前缀和。

#include
#include
using namespace std;
const int maxn=105;
int n,m,T,fa[maxn],w[maxn];
inline char nc()
{
    static char buf[100000],*l,*r;
    if (l==r) r=(l=buf)+fread(buf,1,100000,stdin);
    if (l==r) return EOF; return *l++;
}
inline int Read()
{
    int res=0,f=1; char ch=nc(),cc=ch;
    while (ch<'0'||ch>'9') cc=ch,ch=nc();
    if (cc=='-') f=-1;
    while (ch>='0'&&ch<='9') res=res*10+ch-48,ch=nc();
    return res*f;
}
int Getfa(int x)
{
    if (x==fa[x]) return x;
    int t=Getfa(fa[x]);
    w[x]+=w[fa[x]]; fa[x]=t;
    return fa[x];
}
void Work()
{
    n=Read(); m=Read();
    memset(w,0,sizeof(w));
    for (int i=0; i<=n; i++) fa[i]=i;
    for (int i=1; i<=m; i++)
    {
        int x=Read()-1,y=Read(),z=Read(),fx=Getfa(x),fy=Getfa(y);
        printf("%d %d %d %d %d %d %d\n",x,y,z,fx,fy,w[x],w[y]);
        if (fx!=fy) {w[fx]=w[y]-w[x]-z; fa[fx]=fy;}
         else if (w[y]-w[x]!=z) {printf("false\n"); return;}
    }
    printf("true\n");
}
void Print()
{
    for (int i=1; i<=n; i++) printf("%d ",w[i]);
}
int main()
{
    freopen("1202.in","r",stdin);
    freopen("1202.out","w",stdout);
    T=Read();
    while (T--) Work(),Print();
    return 0;
}