Charlie's Case Study : Fixing Memory Leaks In C++

Here comes the Success story of a third-year computer science student from California who was struggling with her C++ assignment.

Introduction : A Confusing Memory Leak Issue

We would like to introduce Charlie, a third-year computer science student from University of Berkeley who was working on a C++ project for her Data Structures class, which involved dynamic memory allocation.

Her program was supposed to handle large amounts of data efficiently but every time she executed the code, it worked fine at first but eventually crashed.

Charlie had no idea what was happening. The code seemed fine, and there were no error messages. As her assignment deadline was approaching, she knew she needed expert help fast. That’s when she reached out to CodingZap.

Problem : Why Was Charlie’s Program Crashing?

As soon as Charlie approached us, we assigned her our one of experienced C++ expert – Sophia Carter and after reviewing her code, Sophia quickly identified the problems in her code.

We are listing the below issues found in Charlie’s code:

Memory Leaks – Her program was allocating memory dynamically using new, but it wasn’t always freeing it with delete. Over time, unused memory kept piling up, leading to high memory usage and eventual crashes.

Dangling Pointers – Some pointers in her program were holding references to deleted memory, which could cause unexpected behavior.

Inefficient Memory Management – Instead of reusing allocated memory, her program kept requesting new memory blocks, causing unnecessary strain on the system.

Why memory leak causes issue often?

Memory leaks in C++ occur when dynamically allocated memory is not properly deallocated, causing the program to consume increasing amounts of memory over time. This typically happens when developers use new or malloc() to allocate memory but forget to free it with delete or free(). Common causes include losing references to allocated memory, improper use of pointers, and failing to release resources in exception-handling scenarios.

Over time, memory leaks can lead to performance degradation, increased RAM usage, and eventually, program crashes, especially in long-running applications. Using smart pointers (unique_ptr, shared_ptr) and memory profiling tools like Valgrind can help prevent these issues.

The Solution: How CodingZap Fixed the Memory Leaks

After rectifying the issues, our expert scheduled one-on-one live tutoring session with our client and guided Charlie step by step to debug and optimize her program. Here’s how we fixed the issue:

Step 1: Identifying Memory Leaks

Using Valgrind, a powerful memory debugging tool, we ran her program and found that it was losing memory on every loop iteration.

Before (Code with Memory Leaks):

Each time processData() was called, a new memory block was allocated but it never got released.

				
					void processData() {
    int* data = new int[100];  // Memory allocated but not freed
    // Processing...
}

Step 2: Fixing the Memory Leaks

To solve this, we made sure every allocated memory block was properly freed before exiting the function.

After (Memory Leaks Fixed):

Now, every dynamically allocated array was freed, preventing memory buildup.

Please refer to the code below:

				
					void processData() {
    int* data = new int[100];  
    // Processing...
    delete[] data; // Properly freeing allocated memory
}

Step 3: Using Smart Pointers for Automatic Memory Management

Now, to eliminate the risk of future memory leaks, we introduced C++ Smart Pointers, which automatically manage memory without requiring manual deletion.

Using unique_ptr for safer memory management:

				
					void processData() {
    std::unique_ptr<int[]> data = std::make_unique<int[]>(100);
    // Processing...
} // Memory automatically freed when function ends

Results :

With these fixes, Charlie’s program became more stable, ran significantly faster, and reduced memory usage by 50%. After resolving the issue, our expert ensured she fully understood the problem and its solution, equipping her to handle similar challenges in future development projects.

Testimonial :

“I was so dead frustrated because my Cpp program kept slowing down and crashing, and I had no clue why. Sophia from CodingZap didn’t just fix my code but she taught me how to prevent memory leaks in the future. Now, I feel confident writing efficient C++ programs!” – Charlie, St. Jose, CA

Conclusion :

At CodingZap, we help students solve real coding challenges—not just by fixing errors, but by tutoring them how to write better code.

Whether you’re struggling with:
✔ Memory leaks and pointers in C++
✔ Complex debugging issues
✔ Optimizing inefficient programs

We’re here to help you master coding with ease!

Need help fixing memory leaks in your C++ code? Click here to get C++ homework and project related help.