Feat: Queue Using One Stack

Readme.md

@@ -1,3 +1 @@
-## This is the file for the Kalpavriksha Program
-
-# here i will be doing the assignments
+### The time complexity for both enqueue and dequeue operations is 𝑂 ( 𝑛 ) in the worst case, and the space complexity is 𝑂 ( 𝑛 ) .

queueUsingOneStack.c

@@ -0,0 +1,107 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+
+typedef struct Stack {
+    int size;
+    int *arr;
+    int top;
+} Stack;
+
+Stack* createStack(int size) {
+    Stack* s = (Stack*) malloc(sizeof(Stack));
+    if (s == NULL) {
+        printf("Memory Not Allocated!!");
+        return NULL;
+    }
+    s->size = size;
+    s->top = -1;
+    s->arr = (int*) malloc(sizeof(int) * size);
+    if (s->arr == NULL) {
+        printf("Memory not allocated to stack array!!\n");
+        free(s);
+        return NULL;
+    }
+    return s;
+}
+
+bool isEmpty(Stack* s) {
+    return s->top == -1;
+}
+
+bool isFull(Stack* s) {
+    return s->top == s->size - 1;
+}
+
+void push(Stack* s, int data) {
+    if (isFull(s)) {
+        printf("Stack Overflow!!\n");
+        return;
+    }
+    s->arr[++s->top] = data;
+}
+
+int pop(Stack* s) {
+    if (isEmpty(s)) {
+        printf("Stack Underflow!!\n");
+        return -1;
+    }
+    return s->arr[s->top--];
+}
+
+void enqueue(Stack* s, int data) {
+    push(s, data);
+    printf("Enqueued: %d\n", data);
+}
+
+int dequeue(Stack* s) {
+    if (isEmpty(s)) {
+        printf("Queue is empty!!\n");
+        return -1;
+    }
+    int x = pop(s);
+    if (isEmpty(s)) {
+        printf("Dequeued: %d\n", x);
+        return x;
+    }
+    int res = dequeue(s);
+    push(s, x);
+    return res;
+}
+
+int main() {
+    int size, choice, value;
+    printf("Enter the size of the queue: ");
+    scanf("%d", &size);
+    Stack* s = createStack(size);
+
+    while (1) {
+        printf("Enter the Choice:- \n");
+        printf("1. Enqueue\n");
+        printf("2. Dequeue\n");
+        printf("3. Exit\n");
+        printf("You Entered: ");
+        scanf("%d", &choice);
+
+        switch (choice) {
+            case 1:
+                printf("Value? ");
+                scanf("%d", &value);
+                enqueue(s, value);
+                break;
+
+            case 2:
+                dequeue(s);
+                break;
+
+            case 3:
+                printf("--EXIT--\n");
+                return 0;
+
+            default:
+                printf("Invalid choice! Please enter again.\n");
+                break;
+        }
+    }
+    return 0;
+}