Find the Minimum Value in a 1D Integer Array

Title: Minimum Element Finder (1D Array)
Level: Easy
Concepts: 1D array traversal, iteration, boundary checks, simple comparison logic, input validation

Scenario

An embedded device periodically collects a batch of sensor readings (integers). Before further processing, you must determine the minimum value in the collected samples. The array length may vary, and the function must handle cases like empty input safely.

Problem Statement

Implement a function that scans a 1D integer array and returns the minimum value found. The function must perform input validation, handle arrays of any valid length, and return an error if the array pointer is invalid or the size is negative.

Requirements

• Use a simple linear scan through the array.
• Inputs:
  • a[] — integer array
  • n — number of elements (may be 0 or more)
• Outputs:
  • *out_min — the smallest integer in the array
• Error handling:
  • If a == NULL, out_min == NULL, or n <= 0, return -1
  • On error: do not modify *out_min
• Must use only the allowed types (int, long, double, char, bool, enum).

Function Details

• Name: find_min_in_array
• Arguments:
  • const int *a
  • int n
  • int *out_min
• Return Value:
  • int — 0 on success, -1 on error.
• Description:
  The function must iterate from index 0 to n-1, track the smallest value encountered, and return it through *out_min.

Solution Approach

• Validate inputs (a != NULL, out_min != NULL, n > 0).
• Initialize local min_value = a[0].
• Iterate using a simple loop:
  • For each a[i], compare with min_value.
  • If smaller, update min_value.
• Store the result into *out_min.
• Return success (0).

Tasks to Perform

1. Validate inputs:
   • If out_min == NULL or a == NULL → return -1.
   • If n <= 0 → return -1.
2. Initialize min_value = a[0].
3. Loop from i = 1 to n-1:
   • If a[i] < min_value, then update.
4. Write final result into *out_min.
5. Return 0.

Test Cases