poj 1094 拓扑排序

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<queue>
#define Maxn 102
#define Maxm 10010
using namespace std;
int graphic[Maxn][Maxn],indegree[Maxn],n,m,e;
char ans[Maxn];
int Topsort()
{
int i,j,k,num,temp,f=0;
temp=0;
for(i=1;i<=n;i++)
{
num=0;
for(j=1;j<=n;j++)
{
if(indegree[j]==0)
num++;
}
if(num>1)
f=1;
for(j=1;j<=n;j++)
{
if(indegree[j]==0)
{
indegree[j]--;
ans[e++]=j+'A'-1;
for(k=1;k<=n;k++)
{
if(graphic[j][k])
indegree[k]--;
}
temp++;
break;
}
}
}
//cout<<"*"<<temp<<endl;
if(temp<n)
return -1;
if(f)
return 0;
return 1;
}
int main()
{
int i,j,a,b;
char str[Maxm][10];
//freopen("ans.txt","w",stdout);
while(scanf("%d%d",&n,&m)!=EOF,n||m)
{
memset(graphic,0,sizeof(graphic));
memset(indegree,0,sizeof(indegree));
e=0;
int temp,pos;
for(i=0;i<m;i++)
{
scanf("%s",&str[i]);
memset(indegree,0,sizeof(indegree));
memset(graphic,0,sizeof(graphic));
for(j=0;j<=i;j++)
{
if(!graphic[str[j][0]-'A'+1][str[j][2]-'A'+1])
{
indegree[str[j][2]-'A'+1]++;
graphic[str[j][0]-'A'+1][str[j][2]-'A'+1]=1;
}
}
e=0;
temp=Topsort();
if(temp==1)
{  //cout<<e<<endl;
pos=i+1;
ans[e]='\0';
break;
}
if(temp==-1)
{
pos=i+1;
break;
}
}
//cout<<i<<"&&"<<endl;
for(i++;i<m;i++)
{
scanf("%s",&str[i]);
//cout<<i<<endl;
}//cout<<temp<<" **"<<endl;
if(temp==-1)
{
printf("Inconsistency found after %d relations.\n",pos);
}
if(temp==1)
{
printf("Sorted sequence determined after %d relations: %s.\n",pos,ans);
}
if(temp==0)
printf("Sorted sequence cannot be determined.\n");
}
return 0;
}

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<queue>
#define Maxn 102
#define Maxm 10010
using namespace std;
struct Edge{
int to,next;
}edge[Maxm];
int graphic[Maxn][Maxn],indegree[Maxn],n,m,e,index[Maxn],r;
char ans[Maxn];
int Topsort()
{
int i,j,k,num,temp,f=0;
temp=0;
for(i=1;i<=n;i++)
{
num=0;
for(j=1;j<=n;j++)
{
if(indegree[j]==0)
num++;
}
if(num>1)
f=1;
for(j=1;j<=n;j++)
{
if(indegree[j]==0)
{
indegree[j]--;
ans[e++]=j+'A'-1;
for(k=index[j];k!=-1;k=edge[k].next)
{
indegree[edge[k].to]--;
}
temp++;
break;
}
}
}
//cout<<"*"<<temp<<endl;
if(temp<n)
return -1;
if(f)
return 0;
return 1;
}
void addedge(int from ,int to)
{
edge[r].to=to;
edge[r].next=index[from];
index[from]=r++;
}
int main()
{
int i,j,a,b;
char str[Maxm][10];
//freopen("ans.txt","w",stdout);
while(scanf("%d%d",&n,&m)!=EOF,n||m)
{
memset(graphic,0,sizeof(graphic));
memset(indegree,0,sizeof(indegree));
memset(index,-1,sizeof(index));
e=0;
int temp,pos;
for(i=0;i<m;i++)
{
scanf("%s",&str[i]);
memset(indegree,0,sizeof(indegree));
memset(graphic,0,sizeof(graphic));
memset(index,-1,sizeof(index));
r=0;
for(j=0;j<=i;j++)
{
if(!graphic[str[j][0]-'A'+1][str[j][2]-'A'+1])
{
addedge(str[j][0]-'A'+1,str[j][2]-'A'+1);
indegree[str[j][2]-'A'+1]++;
graphic[str[j][0]-'A'+1][str[j][2]-'A'+1]=1;
}
}
e=0;
temp=Topsort();
if(temp==1)
{  //cout<<e<<endl;
pos=i+1;
ans[e]='\0';
break;
}
if(temp==-1)
{
pos=i+1;
break;
}
}
//cout<<i<<"&&"<<endl;
for(i++;i<m;i++)
{
scanf("%s",&str[i]);
//cout<<i<<endl;
}//cout<<temp<<" **"<<endl;
if(temp==-1)
{
printf("Inconsistency found after %d relations.\n",pos);
}
if(temp==1)
{
printf("Sorted sequence determined after %d relations: %s.\n",pos,ans);
}
if(temp==0)
printf("Sorted sequence cannot be determined.\n");
}
return 0;
}