A simple binary search example.

bsearch.c

#include <stdio.h>


int* binary_search(int* v, int n, int x){
	int m = n/2;

	if(x == *(v+m))
		return v;
	else if(n == 1)
		return NULL;
	else if(x < *(v+m))
		return binary_search(v, m, x);
	else
		return binary_search(v+m, n-m, x);
	
}

int main() {
	int vector[10] = {2, 5, 7, 8, 10, 11, 100};
		// should be ordered!
	int size = 7, i;
	int* found;
	int search;

	printf("The vector is:\n");
	for(i = 0; i < size; i++){
		printf("%i ", vector[i]);
	}
	printf("\nWhich is the value you wish to search for?\n");

	while(1){
		if(scanf("%i", &search) < 1) break;
		found = binary_search(vector, 7, search);
		
		if(found != NULL)
			printf("Value found!\n");
		else printf("Value is not in the vector!\n");
	}

	return 0;
}

Looks good , i can't find something to disturb me.