Mega Code Archive
Binary search of an array
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#include <stdio.h>
#define SIZE 15
int binarySearch( const int b[], int searchKey, int low, int high );
int main() {
int a[ SIZE ];
int i;
int key = 10;
int result = -1;
for ( i = 0; i < SIZE; i++ ) {
a[ i ] = 2 * i;
}
result = binarySearch( a, key, 0, SIZE - 1 );
if ( result != -1 ) {
printf( "\n%d found in array element %d\n", key, result );
} else {
printf( "\n%d not found\n", key );
}
return 0;
}
int binarySearch( const int b[], int searchKey, int low, int high )
{
int middle;
while ( low <= high ) {
middle = ( low + high ) / 2;
if ( searchKey == b[ middle ] ) {
return middle;
} else if ( searchKey < b[ middle ] ) {
high = middle - 1;
} else {
low = middle + 1;
}
}
return -1;
}
10 found in array element 5
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