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鎷撴墤鎺掑簭錛岃兘紜畾欏哄簭鐨勬儏鍐墊槸鍦ㄦ嫇鎵戞帓搴忔椂姣忎釜鏃跺埢鍏ュ害涓?鐨勯《鐐瑰彧鏈変竴涓?br>
#include<iostream>#include<fstream>using namespace std;int n,degree[30],res[30];struct Node
{
int pos; Node *next;
}node[30];void insert(char a,char b){ int aa=a-'A'; int bb=b-'A'; Node *p=new Node; p->pos=bb; p->next=node[aa].next; node[aa].next=p;}int top_sort(){ bool flag=false;
int in[30]={0}; int i,tmp,top,sta[100]; for(i=0,top=0;i<n;i++) { in[i]=degree[i]; if(in[i]==0) sta[top++]=i;
} if(top>1) flag=true;/**//* for(i=0;i<n;i++) printf("%d ",in[i]); puts("");*/ for(i=0;i<n;i++) { if(top==0) return -1; if(top>1) flag=true; tmp=sta[--top]; res[i]=tmp; Node *p=node[tmp].next; while(p) { if(--in[p->pos]==0) sta[top++]=p->pos; p=p->next; } } if(flag) return 0; return 1;}int main(){ bool flag,incon; int i,m,num=0,tmp; char str[4]; ifstream input; input.open("in.txt");// while(input>>n>>m) while(scanf("%d%d",&n,&m)) { if(n==0&&m==0) break; flag=incon=false; memset(degree,0,sizeof(degree)); for(i=0;i<n;i++) node[i].next=NULL; for(i=1;i<=m;i++) { scanf("%s",str); // input>>str; if((!flag)&&(!incon)) { degree[str[2]-'A']++; insert(str[0],str[2]); tmp=top_sort(); if(tmp==-1) { num=i; incon=true; } else if(tmp==1) { num=i; flag=true; } } } if(flag) { printf("Sorted sequence determined after %d relations: ",num); for(i=0;i<n;i++) printf("%c",'A'+res[i]); puts("."); } else if(incon) printf("Inconsistency found after %d relations.\n",num); else printf("Sorted sequence cannot be determined.\n"); } system("pause"); return 0;}]]>