C PROGRAMMING PROGRAM • ARRAYS, SEARCHING & SORTING

Merge Two Arrays

Learn how to merge two arrays using a clear C program.

BeginnerArraysMergeSequential copy

PROBLEM UNDERSTANDING

Input and expected output

Sample input

Sample output

1 3 5 2 4 6 8

COMPLETE C PROGRAM

Complete C implementation

#include <stdio.h>

int main(void)
{
    int firstSize, secondSize, first[50], second[50], merged[100];

    scanf("%d", &firstSize);
    if (firstSize < 0 || firstSize > 50) return 1;
    for (int index = 0; index < firstSize; index++) scanf("%d", &first[index]);
    scanf("%d", &secondSize);
    if (secondSize < 0 || secondSize > 50) return 1;
    for (int index = 0; index < secondSize; index++) scanf("%d", &second[index]);
    for (int index = 0; index < firstSize; index++) merged[index] = first[index];
    for (int index = 0; index < secondSize; index++) merged[firstSize + index] = second[index];
    for (int index = 0; index < firstSize + secondSize; index++)
        printf("%d%c", merged[index], index == firstSize + secondSize - 1 ? '\n' : ' ');
    return 0;
}

CURRENT STEP

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EXPECTED OUTPUT FOR THE SAMPLE

1 3 5 2 4 6 8

0%Step 0 of 0

PROGRAM EXPLANATION

Algorithm and explanation

Read the required input values.
Copy the first array, then append the second array starting at the first array's size.
Display the computed result.

Copy the first array, then append the second array starting at the first array's size.

EFFICIENCY

Time and space complexity

Time complexity

O(n)

Auxiliary space

O(n)

DEBUGGING CHECKLIST

Common mistakes

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Use the correct format specifier for every variable.

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Initialize variables before using their values.

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Check braces, semicolons and input order carefully.

Try it yourself

Practice: Run the program with the sample input, predict its output, and then test one boundary case of your own.