#include <stdio.h>

int searchNum(int *arr, int num, int len);

int main(int argc, const char * argv[]) {

    

    int a[9] = {3, 0, -5, 88, 99, 100, -10, 50, 20};

    int i = 0, j = 0;

    int num;

    printf("please input a number: \n");

    scanf("%d", &num);

    int temp;

    int length = sizeof(a) / sizeof(a[0]);

    for(; i < length; i++){

        for(j = i + 1; j < length; j++){

            if(a[i] > a[j]){

                temp = a[i];

                a[i] = a[j];

                a[j] = temp;

            }

        }

    }

    

    int res = searchNum(a, num, length);

    

    if(res != -1){

        printf("Find it.\n");

    }else{

        printf("Not found.\n");

    }

    

    return 0;

}

int searchNum(int *arr, int num, int len){

    int max = len-1, min = 0;

    int mid = (max + min) * 0.5;

    while(num != arr[mid]){

        if(num > arr[mid]){

            min = mid + 1;

        }else if(num < arr[mid]){

            max = mid - 1;

        }

        if(min > max){

            return -1;

        }

        mid = (max + min) * 0.5;

    }

    return mid;

    

}