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最小生成树计数 比生成树计数 多了边的权值
bzoj 1016 http://www.lydsy.com/JudgeOnline/problem.php?id=1016
#include <map>
#include <stack>
#include <queue>
#include <math.h>
#include <vector>
#include <string>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <iostream>
#include <algorithm>
#define N 405
#define M 4005
#define E
#define inf 0x3f3f3f3f
#define dinf 1e10
#define linf (LL)1<<60
#define LL long long
#define clr(a,b) memset(a,b,sizeof(a))
using namespace std;const LL mod=31011;
struct Edge
{int a,b,c;bool operator<(const Edge & t)const{return c<t.c;}
}edge[M];
int n,m;
LL ans;
int fa[N],ka[N],vis[N];
LL gk[N][N],tmp[N][N];
vector<int>gra[N];int findfa(int a,int b[]){return a==b[a]?a:b[a]=findfa(b[a],b);}LL det(LL a[][N],int n)
{for(int i=0;i<n;i++)for(int j=0;j<n;j++)a[i][j]%=mod;long long ret=1;for(int i=1;i<n;i++){for(int j=i+1;j<n;j++)while(a[j][i]){LL t=a[i][i]/a[j][i];for(int k=i;k<n;k++)a[i][k]=(a[i][k]-a[j][k]*t)%mod;for(int k=i;k<n;k++)swap(a[i][k],a[j][k]);ret=-ret;}if(a[i][i]==0)return 0;ret=ret*a[i][i]%mod;//ret%=mod;}return (ret+mod)%mod;
}int main()
{while(scanf("%d%d",&n,&m)==2){if(n==0 && m==0 && mod==0)break;memset(gk,0,sizeof(gk));memset(tmp,0,sizeof(tmp));memset(fa,0,sizeof(fa));memset(ka,0,sizeof(ka));memset(tmp,0,sizeof(tmp));for(int i=0;i<N;i++)gra[i].clear();for(int i=0;i<m;i++)scanf("%d%d%d",&edge[i].a,&edge[i].b,&edge[i].c);sort(edge,edge+m);for(int i=1;i<=n;i++)fa[i]=i,vis[i]=0;int pre=-1;ans=1;for(int h=0;h<=m;h++){if(edge[h].c!=pre||h==m){for(int i=1;i<=n;i++)if(vis[i]){int u=findfa(i,ka);gra[u].push_back(i);vis[i]=0;}for(int i=1;i<=n;i++)if(gra[i].size()>1){for(int a=1;a<=n;a++)for(int b=1;b<=n;b++)tmp[a][b]=0;int len=gra[i].size();for(int a=0;a<len;a++)for(int b=a+1;b<len;b++){int la=gra[i][a],lb=gra[i][b];tmp[a][b]=(tmp[b][a]-=gk[la][lb]);tmp[a][a]+=gk[la][lb];tmp[b][b]+=gk[la][lb];}long long ret=(long long)det(tmp,len);ret%=mod;ans=(ans*ret%mod)%mod;for(int a=0;a<len;a++)fa[gra[i][a]]=i;}for(int i=1;i<=n;i++){ka[i]=fa[i]=findfa(i,fa);gra[i].clear();}if(h==m)break;pre=edge[h].c;}int a=edge[h].a,b=edge[h].b;int pa=findfa(a,fa),pb=findfa(b,fa);if(pa==pb)continue;vis[pa]=vis[pb]=1;ka[findfa(pa,ka)]=findfa(pb,ka);gk[pa][pb]++;gk[pb][pa]++;}int flag=0;for(int i=2;i<=n&&!flag;i++)if(ka[i]!=ka[i-1])flag=1;ans%=mod;printf("%lld\n",flag?0:ans);}return 0;
}
hdu 4408 http://acm.hdu.edu.cn/showproblem.php?pid=4408
#include <map>
#include <stack>
#include <queue>
#include <math.h>
#include <vector>
#include <string>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <iostream>
#include <algorithm>
#define N 405
#define M 4005
#define E
#define inf 0x3f3f3f3f
#define dinf 1e10
#define linf (LL)1<<60
#define LL long long
#define clr(a,b) memset(a,b,sizeof(a))
using namespace std;LL mod;
struct Edge
{int a,b,c;bool operator<(const Edge & t)const{return c<t.c;}
}edge[M];
int n,m;
LL ans;
int fa[N],ka[N],vis[N];
LL gk[N][N],tmp[N][N];
vector<int>gra[N];int findfa(int a,int b[]){return a==b[a]?a:b[a]=findfa(b[a],b);}LL det(LL a[][N],int n)
{for(int i=0;i<n;i++)for(int j=0;j<n;j++)a[i][j]%=mod;long long ret=1;for(int i=1;i<n;i++){for(int j=i+1;j<n;j++)while(a[j][i]){LL t=a[i][i]/a[j][i];for(int k=i;k<n;k++)a[i][k]=(a[i][k]-a[j][k]*t)%mod;for(int k=i;k<n;k++)swap(a[i][k],a[j][k]);ret=-ret;}if(a[i][i]==0)return 0;ret=ret*a[i][i]%mod;//ret%=mod;}return (ret+mod)%mod;
}int main()
{while(scanf("%d%d%lld",&n,&m,&mod)==3){if(n==0 && m==0 && mod==0)break;memset(gk,0,sizeof(gk));memset(tmp,0,sizeof(tmp));memset(fa,0,sizeof(fa));memset(ka,0,sizeof(ka));memset(tmp,0,sizeof(tmp));for(int i=0;i<N;i++)gra[i].clear();for(int i=0;i<m;i++)scanf("%d%d%d",&edge[i].a,&edge[i].b,&edge[i].c);sort(edge,edge+m);for(int i=1;i<=n;i++)fa[i]=i,vis[i]=0;int pre=-1;ans=1;for(int h=0;h<=m;h++){if(edge[h].c!=pre||h==m){for(int i=1;i<=n;i++)if(vis[i]){int u=findfa(i,ka);gra[u].push_back(i);vis[i]=0;}for(int i=1;i<=n;i++)if(gra[i].size()>1){for(int a=1;a<=n;a++)for(int b=1;b<=n;b++)tmp[a][b]=0;int len=gra[i].size();for(int a=0;a<len;a++)for(int b=a+1;b<len;b++){int la=gra[i][a],lb=gra[i][b];tmp[a][b]=(tmp[b][a]-=gk[la][lb]);tmp[a][a]+=gk[la][lb];tmp[b][b]+=gk[la][lb];}long long ret=(long long)det(tmp,len);ret%=mod;ans=(ans*ret%mod)%mod;for(int a=0;a<len;a++)fa[gra[i][a]]=i;}for(int i=1;i<=n;i++){ka[i]=fa[i]=findfa(i,fa);gra[i].clear();}if(h==m)break;pre=edge[h].c;}int a=edge[h].a,b=edge[h].b;int pa=findfa(a,fa),pb=findfa(b,fa);if(pa==pb)continue;vis[pa]=vis[pb]=1;ka[findfa(pa,ka)]=findfa(pb,ka);gk[pa][pb]++;gk[pb][pa]++;}int flag=0;for(int i=2;i<=n&&!flag;i++)if(ka[i]!=ka[i-1])flag=1;ans%=mod;printf("%lld\n",flag?0:ans);}return 0;
}
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