CodeBhavya

DATA STRUCTURES PROGRAM • ARRAY TECHNIQUES

Find the Maximum Fixed-Window Sum

Learn how to find the maximum fixed-window sum using a clear C program.

BeginnerSliding windowFixed sizeRolling sum

PROBLEM UNDERSTANDING

Input and expected output

Sample input
No input required
Sample output
Maximum window sum = 9

COMPLETE C PROGRAM

Complete C implementation

dsa-fixed-sliding-window-sum.c
Open in compiler
#include <stdio.h>

int main(void)
{
    int values[] = {2, 1, 5, 1, 3, 2};
    int window_size = 3, window_sum = 0;
    for (int index = 0; index < window_size; index++) window_sum += values[index];
    int best = window_sum;
    for (int index = window_size; index < 6; index++) {
        window_sum += values[index] - values[index - window_size];
        if (window_sum > best) best = window_sum;
    }
    printf("Maximum window sum = %d\n", best);
    return 0;
}

GUIDED CODE TOUR • NOT LIVE EXECUTION

Study the program line by line

Use the real compiler button above to run and debug with different inputs.

CURRENT STEP

Select Start to walk through the important lines.

SELECTED LINE

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EXPECTED OUTPUT FOR THE SAMPLE

Maximum window sum = 9
0%Step 0 of 0

PROGRAM EXPLANATION

Algorithm and explanation

  1. Read the required input values.
  2. Add the entering value and remove the leaving value instead of recalculating each window.
  3. Display the computed result.

Add the entering value and remove the leaving value instead of recalculating each window.

EFFICIENCY

Time and space complexity

Time complexity

O(n)

Auxiliary space

O(1)

DEBUGGING CHECKLIST

Common mistakes

Check this

Use the correct format specifier for every variable.

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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.