Java Program to Check array sorted (non-decreasing) with Explanation

Java Easy Arrays 22 views

1 min read 169 words

This problem helps you practice core Java fundamentals in a practical way. It builds intuition around non-decreasing, sorted, true. Let’s break it down step by step so you can implement it confidently.

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Problem Statement

Task: return true if the array is sorted in non-decreasing order. Compare adjacent elements.

Input Format

An integer n (size of array)
Then n integers (array elements)

Output Format

true if array is sorted in non-decreasing order, otherwise false.

Constraints

• n ≥ 1

• Non-decreasing means: arr[i]

Concept Explanation

An array is non-decreasing if no element is greater than the next one.
We only compare adjacent elements

Step-by-Step Logic

1.Read array size n.

2.Read n elements into the array.

3.Loop from index 0 to n-2.

4.For each index i:

• If arr[i] > arr[i+1], return false.

5.If loop finishes without finding a problem, return true.

Code Solution

This explanation is written for learning purposes and to help beginners understand the concept clearly.

static boolean isSorted(int[] a){for(int i=1;i<a.length;i++) if(a[i]<a[i-1]) return false;return true;}

Output Example

Input:

5 1 2 2 4 5

Output:

true

Common Mistakes

- Misreading input/output format.
- Not handling constraints and edge cases.
- Off-by-one errors in loops.
- Forgetting to reset variables between test cases (if any).

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