hdu 1116 Play on Words
http://acm.hdu.edu.cn/showproblem.php?pid=1116
1 #include <cstdio> 2 #include <cstring> 3 #include <algorithm> 4 #define maxn 1000 5 using namespace std; 6 7 int f[maxn],in[maxn],ou[maxn],a[maxn]; 8 bool vis[maxn]; 9 int n; 10 char str[maxn]; 11 12 int find(int x) 13 { 14 if(x==f[x]) return x; 15 return f[x]=find(f[x]); 16 } 17 18 void union1(int x,int y) 19 { 20 int fx=find(x); 21 int fy=find(y); 22 if(fx!=fy) 23 f[fx]=fy; 24 } 25 26 void inti() 27 { 28 for(int i=0; i<26; i++) 29 f[i]=i; 30 } 31 32 int main() 33 { 34 int t; 35 scanf("%d",&t); 36 while(t--) 37 { 38 scanf("%d",&n); 39 inti(); 40 memset(in,0,sizeof(in)); 41 memset(ou,0,sizeof(ou)); 42 memset(vis,false,sizeof(vis)); 43 for(int i=0; i<n; i++) 44 { 45 scanf("%s",str); 46 int k=strlen(str); 47 ou[str[0]-'a']++; 48 in[str[k-1]-'a']++; 49 vis[str[0]-'a']=true; 50 vis[str[k-1]-'a']=true; 51 union1(str[0]-'a',str[k-1]-'a'); 52 } 53 int ans=0; 54 for(int i=0; i<26; i++) 55 { 56 if(vis[i]&&f[i]==i) 57 ans++; 58 } 59 if(ans>1) 60 { 61 printf("The door cannot be opened.\n"); 62 continue; 63 } 64 int m1=0,m2=0; 65 bool flag=true; 66 for(int j=0; j<26; j++) 67 { 68 if(vis[j]&&in[j]!=ou[j]) 69 { 70 if(in[j]-ou[j]==1) 71 { 72 m1++; 73 } 74 else if(ou[j]-in[j]==1) 75 { 76 m2++; 77 } 78 else flag=false; 79 } 80 } 81 if(flag&&((m1==0&&m2==0)||(m1==1&&m2==1))) 82 printf("Ordering is possible.\n"); 83 else 84 printf("The door cannot be opened.\n"); 85 } 86 return 0; 87 }
