Просмотр исходного текста страницы C/Data Structure Algorithm/Search

== Binary search:bsearch in stdlib.h==


   
<source lang="cpp">

#include <stdio.h>
#include <stdlib.h>
int values[] = { 1 , 2 , 3, 4 , 9 , 10 };
int compare (const void * a, const void * b) {
  return ( *(int*)a - *(int*)b );
}
int main ()
{
  int *pos;
  int key = 9;
  
  pos = (int*) bsearch (&key, values, 6, sizeof (int), compare);
  
  if ( pos != NULL )
    printf ("%d is in the array", *pos);
  else
    printf ("%d is not in the array", key);
  
  return 0;
}
           
       </source>


==The Binary search==


   
<source lang="cpp">

int binary_search(char *items, int count, char key)
{
  int low, high, mid;
  low = 0; high = count-1;
  while(low <= high) {
    mid = (low+high)/2;
    if(key < items[mid]) high = mid-1;
    else if(key > items[mid]) low = mid+1;
    else return mid; /* found */
  }
  return -1;
}

           
       </source>