UVa中国麻将（Chinese Mahjong,Uva 11210）

简单的回溯题

 #include<iostream>
 #include<cstdio>
 #include<cstring>
 #include<algorithm>
 using namespace std;

 char *mahjong[]={
                                 "1T","2T","3T","4T","5T","6T","7T","8T","9T",
                                 "1S","2S","3S","4S","5S","6S","7S","8S","9S",
                                 "1W","2W","3W","4W","5W","6W","7W","8W","9W",
                                 "DONG","NAN","XI","BEI",
                                 "ZHONG","FA","BAI"
                                 };

 int convert(char *s)//映射处理
 {
     for(int i=;i<;i++)
         if(strcmp(mahjong[i],s)==)
             return i;
     return -;
 }

 int c[];

 bool search(int dep)
 {
     for(int i=;i<;i++)//枚举刻子
         if(c[i]>=)
         {
             if(dep==) return true;
             c[i]-=;
             if(search(dep+)) return true;
             c[i]+=;
         }
     for(int i=;i<;i++)//枚举顺子
         if(i%<=&&c[i]>=&&c[i+]>=&&c[i+]>=)
         {
             if(dep==) return true;
             c[i]--;c[i+]--;c[i+]--;
             if(search(dep+)) return true;
             c[i]++;c[i+]++;c[i+]++;
         }
     return false;
 }

 bool check()
 {
     for(int i=;i<;i++)//枚举将牌
         if(c[i]>=)
         {
             c[i]-=;
             if(search()) return true;
             c[i]+=;
         }
     return false;
 }

 int main()
 {
     int casen=;
     int mj[];
     char s[];
     bool ok;
     while(cin>>s)
     {
         if(s[]=='') break;
         printf("Case %d:",++casen);
         mj[]=convert(s);
         for(int i=;i<;i++)
         {
             cin>>s;
             mj[i]=convert(s);
         }
         ok=false;
         for(int i=;i<;i++)//枚举听牌
         {
             memset(c,,sizeof(c));
             for(int j=;j<;j++) c[mj[j]]++;
             if(c[i]>=) continue;
             c[i]++;
             if(check())
             {
                 ok=true;
                 printf(" %s",mahjong[i]);
             }
             c[i]--;
         }
         if(!ok)
             printf(" Not ready");
         printf("\n");
     }
     return ;
 }