Hi! I'm new to C-programming (Computer Science freshman) and we have this one assignment where we have to use functions to determine if a user-input array is arranged (monotonically non-increasing/non-decreasing) or not. If it's arranged, we have to use another function to perform a binary search to look for a "key" integer in the array. If it's not arranged in any way, we have to use linear search. I got the binary search and linear search down. I think I also got how to determine if it's arranged or not. What I don't understand is how to use them in functions and how to call them out in my main. HELP!

This is my code so far. When I compile it, no errors come out. But when I try to run it, it won't work. It only works until the part where I enter the "key" I need to look for.Code:#include <stdio.h> #include <conio.h> int main() { //scans for length of array int n; scanf("%d", &n); //gets elements of array int arr[n]; int i; for(i=0;i<n;i++) { scanf("%d",&arr[i]); } //gets target/key int key; scanf("%d", &key); //check if the elements are sorted in any order int option; option = is_ordered(); //if elements are sorted, use binary search if(option == 0 || option == 1) binary_search(); else linear_search(); //if target/key is found in list, output "FOUND at index i" //for some 0<=i<n, ouput "NOT FOUND" return(0); } int is_ordered(int arr[], int option) { int i; int n; for(i=0;i<n;i++) { if(arr[i] <= arr[i+1]) option = 0; //non-increasing else if(arr[i] >= arr[i+1]) option = 1; //non-decreasing else option = -1; //no order --> LINEAR SEARCH } return (option); } int linear_search(int arr[], int n, int key) { int i; for(i=0;i<n;i++) { if(key==arr[i]) printf("FOUND at index %d\n", i); else printf("Not found\n"); } return(0); } int binary_search(int arr[], int n, int key) { int first, last, middle; first = 0; last = n - 1; middle = (first+last)/2; while( first <= last ) { if ( arr[middle] < key ) first = middle + 1; else if ( arr[middle] == key ) { printf("%d found at index %d\n", key, middle+1); break; } else last = middle - 1; middle = (first + last)/2; } if ( first > last ) printf("Not found\n", key); return 0; }