Finding minimum element in an integer array

Question

What is wrong in the following program? Why isn't it returning smallest element as i have tried to implement. Kindly spot the errors.Please tell me the errors regarding the logic and the syntax.

#include<stdio.h>
int ArrayMinimum(int a[], size_t size);
#define SIZE 9
int main()
{
    int a[SIZE];
    for (int i = 0; i < SIZE; i++)
    {
        a[i] = 1 + rand() % 99;
        printf("%d  ", a[i]);
    }
    printf("\n\nThe smallest number of the array is %d  \n", ArrayMinimum(a, SIZE));
}
int ArrayMinimum(int a[], size_t size)
{
    if (size == 1)
    {
        return a[0];
    }
    for (int i = 0; i <= size ; i++)
    {
        if (a[i] > a[i + 1])
        {
            int temp = a[i + 1];
            a[i + 1] = a[i];
            a[i] = temp;
        }
    }
    int b[] = { 0 };
    for (int y = 0; y < size; y++)
    {
        b[y] = a[y];
    }
    ArrayMinimum(b, size -1 );

}

`int i = 0; i <= size...` - you are off by 1. Array last element is on `size-1` index. Adding `1` to it in the loop worsens the problem. — Eugene Sh., Dec 03 '18 at 18:38
Your code is weird modification of bubble sort (recursion? Why?) and not for finding minimum. Please explain to yourself what it is supposed to do and how. — Eugene Sh., Dec 03 '18 at 18:51
Possible duplicate of [Finding the smallest number in an array of integers](https://stackoverflow.com/questions/4710795/finding-the-smallest-number-in-an-array-of-integers) — vinS, Dec 03 '18 at 18:53
well , after iterating through the whole for loo, the last element (largest) will be sorted, and then I just remove it and recall the function to find the largest of the remaining array until the array size is 1 (only contains smallest element). I don't know if it's right (just new to programming). — MM fierce, Dec 03 '18 at 18:57
But now I can understand that my recursion is wrong. Thank you. — MM fierce, Dec 03 '18 at 18:58

score 1 · Answer 1 · answered Dec 03 '18 at 19:14

Your function is defined to return an int; and it will return an integer value, if and only if size == 1.

If size has another value, it will not return anything at all!
Where is a second return statement?

There are other substantial problems, such as the size of Array b is not well defined, and you overwrite memory there.

score 0 · Answer 2 · answered Dec 03 '18 at 19:03

You have't put #include <stdlib.h> at the top of your file and as a result, the functions you called were assumed to accept an unknown number of arguments and return a value of type int. This causes undefined behavior.

Implicit declaration of functions srand, rand and system

Also your ArrayMinimum() is wrong.The SIZE constant is always equal to 9 and it gets passed in this method and used by the size variable.Hence it will never satisfy the 'if' condition of this method.With that the BubbleSort mechanism you have implemented is also wrong.Your code just swaps the values only once.

Use this approach to find the minimum of the array:-

minimum = array[0];

    for (c = 1; c < size; c++)
    {
        if (array[c] < minimum)
        {
           minimum = array[c];
           location = c+1;
        }
    }

score 0 · Answer 3 · answered Dec 03 '18 at 20:52

Your ArrayMinimum logic is attempting to sort the array and has logical issues with no return defined if size > 1.

If the purpose is to return the minimum value, a simpler logic can be as follows.

int ArrayMinimum(int a[], size_t size)
{
    int min = a[0];
    if (size == 1)
    {
        return a[0];
    }


    for (int i = 1; i < size ; i++)
    {
        if (a[i] < min)
        {
            min = a[i];
        }
    }
    return min;

}

Finding minimum element in an integer array

3 Answers3