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Print's that 'e' is the least char. why doesn't this work?

 
  #define LEAST(x,y) ((x) < (y) ? (x) : (y))

   char *puzzle = "A real puzzle";
   int main()
  {
      int least=10000;
      char *p = puzzle;       

      while( *p  )              
           least = LEAST( least, *p++ );              
     
      printf( "The least char is '%c'\n", least );
      return 0;
  }
0
ccooney
Asked:
ccooney
1 Solution
 
Kent OlsenData Warehouse Architect / DBACommented:


Try changing the check to this:

     while( *p  )            
           least = LEAST(least, *(p++));            


You want to increment the pointer, not the data.


Kent

0
 
brettmjohnsonCommented:
There are several problems with this code:

1) Beware of macro side effects.  Notice that after the macro substitution the code is
          least = ((least) < (*p++) ? (least) : (*p++));

Notice that p gets incremented twice, once in the test, and again if the test fails.


2) When comparing characters, the ASCII collating order is observed.  In the string
"A real puzzle", the space character would be considered "least" by this definition.
(space has the ASCII code 32 whereas 'e' has ASCII code 101)

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