C PROGRAMMING PROGRAM • POINTERS & DYNAMIC MEMORY

Find Array Sum Using Pointer Arithmetic

Learn how to find array sum using pointer arithmetic using a clear C program.

IntermediatePointersPointer arithmeticArrays

PROBLEM UNDERSTANDING

Input and expected output

Sample input

5
10 20 30 40 50

Sample output

Sum = 150

COMPLETE C PROGRAM

Complete C implementation

#include <stdio.h>

int main(void)
{
    int size, values[100];
    long long sum = 0;

    scanf("%d", &size);
    if (size < 1 || size > 100) return 1;
    for (int index = 0; index < size; index++) scanf("%d", values + index);
    for (int *current = values; current < values + size; current++) sum += *current;
    printf("Sum = %lld\n", sum);
    return 0;
}

CURRENT STEP

Select Start to walk through the important lines.

SELECTED LINE

No line selected

EXPECTED OUTPUT FOR THE SAMPLE

Sum = 150

0%Step 0 of 0

PROGRAM EXPLANATION

Algorithm and explanation

Read the required input values.
Move a pointer through the array and add each dereferenced value.
Display the computed result.

Move a pointer through the array and add each dereferenced value.

EFFICIENCY

Time and space complexity

Time complexity

O(n)

Auxiliary space

O(n)

DEBUGGING CHECKLIST

Common mistakes

Check this

Use the correct format specifier for every variable.

Check this

Initialize variables before using their values.

Check this

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.