Priority Queue Introduction and Concept in DSA C - Build from Scratch

Priority Queue Introduction and Concept

📖 Scenario: Imagine you are managing a hospital emergency room. Patients arrive with different levels of urgency. You want to treat the most urgent patients first. This is a perfect use case for a priority queue.

🎯 Goal: You will build a simple priority queue using an array in C. You will insert patients with their urgency levels and then remove the patient with the highest urgency.

📋 What You'll Learn

Create an array to hold patient urgencies

Create a variable to track the number of patients

Write a function to insert a patient urgency into the queue

Write a function to remove and return the highest urgency patient

Print the queue after insertions and after removal

💡 Why This Matters

🌍 Real World

Priority queues are used in real life to manage tasks that need to be done in order of importance, like emergency rooms or printer job scheduling.

💼 Career

Understanding priority queues helps in software development roles that involve task scheduling, resource management, and real-time systems.

1

Create the initial data structure

Create an integer array called priorityQueue with size 5 and an integer variable called size initialized to 0.

DSA C

int priorityQueue[5];
int size = 0;
// Your code here

Hint

Use int priorityQueue[5]; to create the array and int size = 0; to track how many patients are in the queue.

2

Add a configuration variable

Create an integer variable called maxSize and set it to 5 to represent the maximum size of the priority queue.

DSA C

int priorityQueue[5];
int size = 0;
int maxSize = 5;
// Your code here

Hint

This variable helps us know the limit of the queue size.

3

Implement the insert function

Write a function called insert that takes an integer value and inserts it into priorityQueue at the end, then increments size. Assume size is less than maxSize.

DSA C

int priorityQueue[5];
int size = 0;
int maxSize = 5;

void insert(int value) {
    // Your code here
}

Hint

Insert the value at the current size index and then increase size by 1.

4

Print the queue after insertions

Write a main function that inserts these urgencies into priorityQueue using insert: 30, 50, 20, 40, 10. Then print all elements in priorityQueue separated by spaces.

DSA C

int priorityQueue[5];
int size = 0;
int maxSize = 5;

void insert(int value) {
    priorityQueue[size] = value;
    size++;
}

int main() {
    // Your code here
    return 0;
}

Hint

Use a for loop to print each element in the queue separated by spaces.