Thread: Check if array is sorted

I need to write a function which checks if the elements in an array are in a monotonous order, I wrote the following program which works for some values but it doesn't work for others. For the current array the output is: "The elements are not sorted", and it should be "The array is decreasing". Any ideas? Also, I'm not sure if I used the correct way of updating the loop (++i), would i++ be better?

Code:

/* Implement the function int isSorted(unsigned t[], unsigned n)
which checks if the array has the elements in a monotonous order (either increasing or decreasing)returning a logical result; */


#include <stdio.h>
#include <stdlib.h>
void isSorted(unsigned t[], unsigned n){
    unsigned counterIncr = 0;
    unsigned counterDecr = 0;
    for(int i = 0; i < n; ++i){
        if(t[i] <= t[i+1])
            counterIncr++;
            else 
                if(t[i] > t[i+1])
                    counterDecr++;


    }
    if(counterIncr == (n-1))
        printf("The array is increasing");
        else
    if(counterDecr == (n-1))
        printf("The array is decreasing");
        else
            printf("The elements are not sorted");
}


int main()
{
    unsigned t[4] = {1, 2, 3, 4};
    isSorted(t, 4);
    return 0;
}