Hdu1181 - 变形课 - 深度优先搜索

#include<stdio.h>#include<string.h>char se[100];int change[30][30];int mark[30][30];int dfs(int n){if(n==12){return 1;}for(int i=0;i<26;i++){if(change[n][i]==1&&mark[n][i]==0){mark[n][i]=1;if(dfs(i)==1){return 1;}}}return -1;}int main(){while(scanf("%s",se)!=EOF){int t;memset(change,0,sizeof(change));memset(mark,0,sizeof(mark));if(se[0]!='0'){t=strlen(se);change[se[0]-'a'][se[t-1]-'a']=1;while(1){scanf("%s",se);if(se[0]=='0'){break;}t=strlen(se);change[se[0]-'a'][se[t-1]-'a']=1;}}if(dfs(1)==1){puts("Yes.");}else{puts("No.");}}}