#include <stdio.h>
#include <stdint.h>
int binary_search(uint8_t *arr, uint8_t n, uint8_t key) {
int i =0;
int start=0;
int stop=n;
int mid=(n/2);
while(1)
{
// printf("Mid: %d arr :%d\n",mid,arr[mid]);
if(arr[mid]>key && mid!=0) //200>250
{
stop=mid;
mid=stop/2;
}
else if(arr[mid]<key && mid!=n-1)//200<250
{
start=mid;
mid=mid+(stop-start)/2;
}
else if(arr[mid]==key) //20==20
{
return mid;
}
else
{
//
return -1;
}
i++;
}
return -1;
}
int main() {
uint8_t n, key;
scanf("%hhu", &n);
uint8_t arr[100];
for (uint8_t i = 0; i < n; i++) {
scanf("%hhu", &arr[i]);
}
scanf("%hhu", &key);
int index = binary_search(arr, n, key);
printf("%d", index);
return 0;
}
Input
6 5 10 15 20 25 30 20
Expected Output
3