#include <stdio.h>
#include <stdint.h>
int binary_search(uint8_t *arr, uint8_t n, uint8_t key) {
// Your logic here
int left = 0;
int right = n - 1;
int middle = ((right - left)/2) + left;
while(left <= right)
{
if(arr[middle] == key) return middle;
else if(arr[middle] > key) right = middle - 1;
else if(arr[middle] < key) left = middle + 1;
middle = ((right - left)/2) + left;
}
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