morse_code.cpp

C/C++程序设计导论（第二版）》程序源文件

// test of morse code converter

#include <iostream.h>
const char DOT='.';
const char DASH='-';
const char COMMA=',';

char MC (char, char, char, char);
char MC1 (char);
char MC2 (char, char);
char MC3 (char, char, char);
char MC4 (char, char, char, char);

void main()
{  char c1, c2, c3, c4, c5;
   while (1)
   {	cin >> c1 >> c2; 
        if (c2 != COMMA)
        {   cin >> c3;
	    if (c3 != COMMA)
   	    {    cin >> c4;
   	         if (c4 != COMMA)
   	             cin >> c5;
   	     }
   	}
   	cout << MC(c1, c2, c3, c4) << endl;
   }
}

char MC (char c1, char c2, char c3, char c4)
{  if (c2 == COMMA)
	return MC1(c1);			// 1 symbol code
   else 
   	if (c3 == COMMA)
	   return MC2(c1, c2);		// 2 symbol code
        else 
           if (c4 == COMMA)
   	       return MC3(c1, c2, c3);	// 3 symbol code
   	   else 
   	       return MC4(c1, c2, c3, c4);	// 4 symbol code
 }
   	
char MC1 (char c1)	// all 1 symbol codes (e, t)
{  if (c1 == DOT) 
	return 'E';
   else return 'T';
}

char MC2 (char c1, char c2)	// all 2 symbol codes (a, m, n, i)
{  if (c1 == DOT)		// (a, i)
	if (c2 == DOT)
	   return ('I');
	else
	   return ('A');
   else				// (m, n)
    	if (c2 == DOT)		
    	   return ('N');
    	else
    	   return ('M');
}

char MC3 (char c1, char c2, char c3)	// all 3 symbol codes (d, g, s, k, w, o, r, u)
{   if (c1 == DOT)			// (s, w, r, u)
	if (c2 == DOT)			// (s, u)
	    if (c3 == DOT)
	    	return ('S');
	    else 
	    	return ('U');
	else				// (w, r)
	    if (c3 == DOT)
	    	return ('R');
	    else 
	    	return ('W');
    else				// (d, g, k, o)
    	if (c2 == DOT)			// (d, k)
    	    if (c3 == DOT)
    	    	return ('D');
    	    else
    	    	return ('K');
    	else				// (g, o)
    	    if (c3 == DOT)
    	    	return ('G');
    	    else
    	    	return ('O');
}

char MC4 (char c1, char c2, char c3, char c4)	// all 4 symbol codes
{
   if (c1 == DOT)			// j, p, v, y, b, h, q, z, c, f, l, x
   	if (c2 == DOT)			// v, h, f
      	    if (c3 == DOT)		// v, h
      	        if (c4 == DOT)
      	            return ('H');
      	        else
      	            return ('V');
      	    else	
      	        return ('F');
   	else				// j, p, l
   	    if (c3 == DOT)
   	        return ('L');
   	    else
   	    	if (c4 == DOT)		// j, p
   	    	    return ('P');
   	    	else
   	    	    return ('J');
   	    	    
   else					// y, b, q, z, c, x
   	if (c2 == DOT)			// y, b, c, x
   	    if (c3 == DOT)		// b, x
   	    	if (c4 == DOT)
   	    	    return ('B');
   	    	 else
   	    	    return ('X');
   	    else			// y, c
   	    	if (c4 == DOT)
   	    	    return ('C');
   	    	else
   	    	    return ('Y');
   	else				// q, z
   	    if (c3 == DOT)
   	    	if (c4 == DOT)
   	    	    return ('Z');
   	        else
   	    	    return ('Q');
   	    else 
   	        return ('?');		// no character
 }