#include

#define LEN 10

#define NOT_FOUND -1

int binary_search(int array[], int len, int key);

int main(void) {

int array[LEN] = {3, 12, 21, 23, 34, 37, 52, 88, 89, 99};

int key, position;

printf("Enter a positive number to be searched for: ");

if ((scanf("%d", &key) != 1 || key < 0)) {

printf("Please enter a positive integer. ");

return 1;

}

position = binary_search(array, LEN, key);

if (position != NOT_FOUND)

printf("%d is at location %d. ", key, position+1);

else

printf("Not found. ");

return 0;

}

int binary_search(int array[], int len, int key) {

int lower, upper, middle;

lower = 0;

upper = LEN - 1;

middle = (lower + upper) / 2;

while (array[middle] != key && lower <= upper) {

if (key < array[middle])

upper = middle - 1;

else

lower = middle + 1;

middle = (lower + upper) / 2;

}

if (array[middle] = key)

return middle;

else

return NOT_FOUND;

}

when I enter 35, the output is no "NOT FOUNF". How to correct the errors?