C++ Sort

STL Sort

sort()

algorithm header

Usage

int main()
{
	int arr[] = { 1, 5, 8, 9, 6, 7, 3, 4, 2, 0 };
	int n = sizeof(arr) / sizeof(arr[0]);
 
	/*Here we take two parameters, the beginning of the
	array and the length n upto which we want the array to
	be sorted*/
	sort(arr, arr + n);
}

Reverse

Use <functional> header and std::greater Src
sort( &arr[0], &arr[n], greater<int>() )
or any boolean return function Queue

qsort()

stdlib.h header

Usage

void qsort(void *base, size_t nitems, size_t size, int (*compar)(const void *, const void*))

• base − This is the pointer to the first element of the array to be sorted.

• nitems − This is the number of elements in the array pointed by base.

• size − This is the size in bytes of each element in the array.

• compar − This is the function that compares two elements. Return INT

• example

#include <stdio.h>
#include <stdlib.h>
 
int values[] = { 88, 56, 100, 2, 25 };
 
int cmpfunc (const void *a, const void *b) {
   return ( *(int*)a - *(int*)b );
}
 
int main () {
   printf("Before sorting the list is: \n");
   for(int n = 0 ; n < 5; n++ ) {
      printf("%d ", values[n]);
   }
 
   qsort(values, 5, sizeof(int), cmpfunc);
 
   printf("\nAfter sorting the list is: \n");
   for(int n = 0 ; n < 5; n++ ) {   
      printf("%d ", values[n]);
   }
}