search - binary search

#include "stdio.h"
#include "string.h"

#define MAX_LIST 50

typedef struct _SqList {
    int data[MAX_LIST];
    int length;
}SqList;

int BinarySearch( SqList* L, int key )
{
    int low = 0;
    int high = L->length - 1;
    int mid;

    while( low <= high )
    {
        mid = ( low + high ) /2;

        if( key < L->data[mid] )
            high = mid - 1;
        else if( key > L->data[mid] )
            low = mid + 1;
        else
            return mid;
    }   
    return MAX_LIST;;
}

int main()
{
    SqList d;
    int intarr[] = {1,10,23,48,65,67,78,79,98,100};
    memcpy( d.data, intarr, sizeof(intarr));
    d.length = sizeof(intarr)/sizeof(int);  
    int index = 0;
    for( ; index < d.length; index++ )
        printf(" %d", d.data[index] );
    int key = 67;
    printf("\nbinary search %d...\n", key);
    index = BinarySearch( &d, key );
    printf("%d is at position %d\n", key, index);
    printf("\n");
    return 0;
}