用于计算 integer 中 1 位的递归程序

Question

I wrote an iterative program that counts of the amount of 1s in the binary of an integer given in argv[1] , my iterative version worked fine but I'm having trouble figuring out how to make the function recursive.

I've tried changing the function with an if statement

#include <stdio.h>
#include <stdlib.h>

int bitcount( int x ) {

  unsigned int count = 0 ;

    count += x & 1;

    x >>= 1 ;

    if ( x > 0 ) {

      bitcount( x ) ;
  }

  return count ;

}

int main( int argc, char *argv[] ) {

  int b ;

  b = atoi( argv[1] ) ;

  b = bitcount ( b ) ;

  printf( "%d\n", b ) ;

  return 0 ;

}

My iterative program gave me the correct answer, but this program will print 1 no matter what number I use.

Answer 1

The problem is that you're not using the returned value of your bitcount function. Change bitcount( x ); for count += bitcount( x );