From 5c109a93183b108ae5cfa792bb21396b39b11f35 Mon Sep 17 00:00:00 2001
From: utkarshalways <utkarshshrma08@gmail.com>
Date: Fri, 31 Jan 2025 16:19:58 +0530
Subject: [PATCH] Feat: Stack Implementation Using Queue

---
 Readme.md         |  10 ++-
 stackUsingQueue.c | 167 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 174 insertions(+), 3 deletions(-)
 create mode 100644 stackUsingQueue.c

diff --git a/Readme.md b/Readme.md
index 2130d1c..78c0eea 100644
--- a/Readme.md
+++ b/Readme.md
@@ -1,3 +1,7 @@
-## This is the file for the Kalpavriksha Program
-
-# here i will be doing the assignments
\ No newline at end of file
+### Push Operation: Time Complexity 𝑂 ( 𝑛 ) 
+### Pop Operation: Time Complexity 𝑂 ( 1 ) 
+### Peek Operation: Time Complexity 𝑂 ( 1 ) 
+### isEmpty Operation: Time Complexity 𝑂 ( 1 ) 
+### isFull Operation: Time Complexity 𝑂 ( 1 ) 
+### Size Operation: Time Complexity 𝑂 ( 1 ) 
+### Space Complexity: 𝑂 ( 𝑛 )
\ No newline at end of file
diff --git a/stackUsingQueue.c b/stackUsingQueue.c
new file mode 100644
index 0000000..189b31a
--- /dev/null
+++ b/stackUsingQueue.c
@@ -0,0 +1,167 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+
+struct Queue {
+    int front;
+    int rear;
+    int size;
+    int *arr;
+};
+
+struct Queue* createQueue(int Size) {
+    struct Queue* q = (struct Queue*) malloc(sizeof(struct Queue));
+    if(q == NULL) {
+        printf("Memory Can't Allocate\n");
+        return NULL;
+    }
+    q->front = -1;
+    q->rear = -1;
+    q->size = Size;
+    q->arr = (int *) malloc(sizeof(int) * Size);
+    if(q->arr == NULL) {
+        free(q); 
+        printf("Memory Can't Allocate\n");
+        return NULL;
+    }
+    return q;
+}
+
+void printQueue(struct Queue* q) {
+    if(isEmpty(q)) {
+        printf("Queue is empty.\n");
+        return;
+    }
+    for(int i = q->front; i <= q->rear; i++) {
+        printf("%d ", q->arr[i]);
+    }
+    printf("\n");
+}
+
+bool isEmpty(struct Queue* q) {
+    return (q->front == -1);
+}
+
+bool isFull(struct Queue* q) {
+    return (q->rear == q->size - 1);
+}
+
+void enqueue(struct Queue* q, int data) {
+    if(isFull(q)) {
+        printf("OverFlow!!\n");
+        return;
+    }
+    if(q->front == -1) {
+        q->front = 0; 
+    }
+    q->arr[++q->rear] = data;
+}
+
+void dequeue(struct Queue* q) {
+    if(isEmpty(q)) {
+        printf("Underflow!!\n");
+        return;
+    }
+    q->front++;
+    
+    if(q->front > q->rear) {
+        q->front = q->rear = -1;
+    }
+}
+
+int peek(struct Queue* q) {
+    if(isEmpty(q)) {
+        printf("Queue is empty.\n");
+        return -1;
+    }
+    printf("Peek Element -> %d\n", q->arr[q->front]);
+    return q->arr[q->front];
+}
+
+void push(struct Queue* q, int data) {
+    if(isFull(q)) {
+        printf("Queue is full, cannot push %d\n", data);
+        return;
+    }
+    
+    enqueue(q, data);
+    
+    // Move all elements behind the newly added element
+    int size = q->rear - q->front + 1;
+    
+    for(int i = 0; i < size - 1; i++) {
+        int temp = q->arr[q->front];
+        dequeue(q);
+        enqueue(q, temp);
+    }
+}
+
+int main() {
+    printf("Size of the Queue? ");
+    
+    int size;
+    scanf("%d", &size);
+    
+    struct Queue* q = createQueue(size);
+    
+    if (q == NULL) return 1;
+    int val; 
+
+    while(1) {
+        printf("Enter the Choice:- \n");
+        printf("1. enqueue\n");
+        printf("2. dequeue\n");
+        printf("3. Peek\n");
+        printf("4. isEmpty\n");
+        printf("5. isFull\n");
+        printf("6. Size\n");
+        printf("Default \n");
+        
+        int choice;
+        printf("You Entered > ");
+        
+        scanf("%d", &choice);
+
+        switch(choice) {
+            case 1: 
+                printf("Value? ");
+                scanf("%d", &val);
+                push(q, val);
+                break;
+
+            case 2: 
+                dequeue(q);    
+                break;
+
+            case 3: 
+                peek(q);
+                break;
+
+            case 4: 
+                isEmpty(q) ? printf("True\n") : printf("False\n");
+                break;
+
+            case 5: 
+                isFull(q) ? printf("True\n") : printf("False\n");
+                break;
+
+            case 6: 
+                if (isEmpty(q)) {
+                    printf("Size: 0\n");
+                } else {
+                    printf("Size: %d\n", (q->rear - q->front + 1));
+                }
+                break;
+
+            default: 
+                printf("--EXIT--\n");
+                free(q->arr);
+                free(q);      
+                return 0;
+        }
+        
+        printQueue(q); 
+    }
+
+    return 0;
+}