POJ 1051

水题。

#include <iostream>
#include <vector>
#include <string.h>
using namespace std;
char Mcode[30][5]={
   /*A-G:*/".-","-...","-.-.","-..",".","..-.","--.",
   /*H-N:*/"....","..",".---","-.-",".-..","--","-.",
   /*O-U:*/"---",".--.","--.-",".-.","...","-","..-",
   /*V-Z:*/"...-",".--","-..-","-.--","--..",
   /*_.,?*/"..--","---.",".-.-","----"
};
int len[30]={
2, 4, 4, 3, 1, 4, 3,4, 2, 4, 3, 4, 2, 2,
3, 4, 4, 3, 3, 1, 3,4, 3, 4, 4, 4,
4, 4, 4, 4
};
int index(char ch){
   if(ch<='Z'&&ch>='A')
       return ch-'A';
   switch(ch){
       case '_':return 26;
       case '.':return 27;
       case ',':return 28;
       case '?':return 29;
   }
   return -1;
}
char* encode(char c,int& n){
   int i=index(c);
   n=len[i];
   return Mcode[i];
}
char decode(char* m,int n){
   for(int i=0;i<30;++i){
       if(n!=len[i]||strncmp(Mcode[i],m,n))
           continue;
       if(i<26)
           return i+'A';
       switch(i){
           case 26: return '_';
           case 27: return '.';
           case 28: return ',';
           case 29: return '?';
       }
   }
   return 0;
}
int main(){
   int N,n;cin>>N;
   for(n=1;n<=N;++n){
       char msg[128],crypt[128*4]={0},*p,*q;
       vector<int> codelen;
       int tmp;
       cin>>msg;
       for(p=msg,q=crypt;*p;++p){
           strcpy(q,encode(*p,tmp));
           codelen.push_back(tmp);
           q+=tmp;
       }
       q=crypt;
       cout<<n<<": ";
       for(int i=codelen.size()-1;i>=0;--i){
           cout<<decode(q,codelen[i]);
           q+=codelen[i];
       }
       cout<<endl;
   }
   return 0;
}