quicksort

This is a discussion on quicksort within the C Programming forums, part of the General Programming Boards category; Hello, I am trying to use the qsort function but i get an error : error : expected expression before ...

  1. #1
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    Join Date
    Feb 2010
    Posts
    115

    quicksort

    Hello,

    I am trying to use the qsort function but i get an error :

    error : expected expression before 'int' on the line where i call the qsort function

    Code:
    int compare(int *a, int *b);
    void schrijfUit (int array[]);
    
    int main (void){
    
    	int array[10] = {1, 5, 23, 43, 3, 3, 543, 2, 542, 53};
    
    	schrijfUit(array);
    	
    	qsort(array,10,sizeof(int),int compare (int *a, int *b));
    	
    	schrijfUit(array);
    	return 0;
    
    }
    
    void schrijfUit (int array[]){
    	
    	int i;
    
    	for (i = 0; i < 10; i++)
    		printf("%i\t", array[i]);
    	printf("\n");	
    
    }
    
    
    int compare(int *a,int *b) {
     	if (*a==*b)
        		return 0;
      	else{
        		if (*a < *b)
            		return -1;
         		else
          			return 1;
    	}
    }
    I think it is a very stupid mistake but i cant see it.

  2. #2
    and the Hat of Guessing tabstop's Avatar
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    14,185
    You need to put in the name of the function, not the prototype.

  3. #3
    C++ Witch laserlight's Avatar
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    After you have fixed that, you should change this:
    Code:
    int compare(int *a, int *b);
    to:
    Code:
    int compare(const void *a, const void *b);
    since that is what qsort expects.
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  4. #4
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    Feb 2010
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    Thank you guys

    it is alive

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