From 9edd9ac19f1b9f8c1a32dad9739bd0cda0d62d21 Mon Sep 17 00:00:00 2001
From: Light <farhan29110511@gmail.com>
Date: Mon, 8 Dec 2025 21:20:15 +0530
Subject: [PATCH] init

---
 circularQueue.c |  93 +++++++++++++++++++++++++++++++++++++++
 linkedStack.c   |  54 +++++++++++++++++++++++
 linkedlist.c    | 113 +++++++++++++++++++++++++++++++++++++++++++++++
 poly.c          |  57 ++++++++++++++++++++++++
 stack.c         | 114 ++++++++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 431 insertions(+)
 create mode 100644 circularQueue.c
 create mode 100644 linkedStack.c
 create mode 100644 linkedlist.c
 create mode 100644 poly.c
 create mode 100644 stack.c

diff --git a/circularQueue.c b/circularQueue.c
new file mode 100644
index 0000000..16cc309
--- /dev/null
+++ b/circularQueue.c
@@ -0,0 +1,93 @@
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+typedef struct {
+  int *keys;
+  int size;
+  int front;
+  int rear;
+
+} cq;
+
+cq *createqueue(int size) {
+  cq *q = (cq *)malloc(sizeof(cq));
+  q->size = size;
+  q->front = -1;
+  q->rear = -1;
+  q->keys = (int *)malloc(size * sizeof(int));
+  return q;
+}
+
+bool isFull(cq *q) { return ((q->rear + 1) % q->size == q->front); }
+bool isEmpty(cq *q) { return q->front == -1; }
+
+void enqueue(cq *q, int v) {
+  if (isFull(q)) {
+    printf("is full");
+  }
+  if (isEmpty(q)) {
+    q->front = 0;
+    q->rear = 0;
+  } else {
+    q->rear = (q->rear + 1) % q->size;
+  }
+  q->keys[q->rear] = v;
+}
+
+int dequeue(cq *q) {
+  if (isEmpty(q)) {
+    printf("Queue is empty! Cannot delete.\n");
+    return -1;
+  }
+  int v = q->keys[q->front];
+  if (q->front == q->rear) {
+    q->front = q->rear = -1;
+
+  } else {
+    q->front = (q->front + 1) % q->size;
+  }
+  return v;
+}
+
+void display(cq *q) {
+  if (isEmpty(q)) {
+    printf("Queue is empty!\n");
+    return;
+  }
+  int i = q->front;
+  while (1) {
+    printf("%d", q->keys[i]);
+    if (i == q->rear) {
+      break;
+    }
+    i = (i + 1) % q->size;
+  }
+}
+int main() {
+  int n;
+  printf("Enter size of queue: ");
+  scanf("%d", &n);
+
+  cq *q = createqueue(n);
+
+  enqueue(q, 10);
+  enqueue(q, 20);
+  enqueue(q, 30);
+  display(q);
+
+  dequeue(q);
+  display(q);
+
+  enqueue(q, 40);
+  enqueue(q, 50);
+  display(q);
+
+  dequeue(q);
+  display(q);
+
+  free(q->keys);
+  free(q);
+
+  return 0;
+}
diff --git a/linkedStack.c b/linkedStack.c
new file mode 100644
index 0000000..931e5f4
--- /dev/null
+++ b/linkedStack.c
@@ -0,0 +1,54 @@
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+struct Node {
+  int data;
+  struct Node *ptr;
+};
+
+struct Node *top = NULL;
+
+void push(int v) {
+  struct Node *new = (struct Node *)malloc(sizeof(struct Node));
+  new->data = v;
+  new->ptr = top;
+  top = new;
+}
+
+int pop() {
+  struct Node *temp = top;
+  int v = temp->data;
+  top = temp->ptr;
+
+  free(temp);
+  return v;
+}
+int peek() {
+  if (top == NULL) {
+    printf("Stack empty\n");
+    return -1;
+  }
+  return top->data;
+}
+
+void display() {
+  struct Node *temp = top;
+  printf("Stack: ");
+  while (temp != NULL) {
+    printf("%d ", temp->data);
+    temp = temp->ptr;
+  }
+  printf("\n");
+}
+int main() {
+  push(10);
+  push(20);
+  push(30);
+  display();
+
+  printf("Popped: %d\n", pop());
+  display();
+
+  printf("Top: %d\n", peek());
+}
diff --git a/linkedlist.c b/linkedlist.c
new file mode 100644
index 0000000..51ffa01
--- /dev/null
+++ b/linkedlist.c
@@ -0,0 +1,113 @@
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+struct Node {
+  struct Node *ptr;
+  int data;
+};
+
+struct Node *head = NULL;
+
+struct Node *createNode(int v) {
+  struct Node *new = (struct Node *)malloc(sizeof(struct Node));
+  new->data = v;
+  new->ptr = NULL;
+  return new;
+}
+
+void insertend(int v, struct Node *new) {
+  if (head == NULL) {
+    head = new;
+    return;
+  }
+  struct Node *temp = head;
+  while (temp->ptr != NULL) {
+    temp = temp->ptr;
+  }
+  temp->ptr = new;
+  new->ptr = NULL;
+}
+
+void insertstart(int v, struct Node *new) {
+  struct Node *temp = head;
+  head = new;
+  new->ptr = temp;
+}
+
+void insert(int v, struct Node *new, int x) {
+  struct Node *temp = head;
+  int w = 0;
+  while (temp->ptr != NULL && w < x) {
+    temp = temp->ptr;
+    w++;
+  }
+  struct Node *temp2 = temp->ptr;
+  temp->ptr = new;
+  new->ptr = temp2;
+}
+void display() {
+  struct Node *temp = head;
+  while (temp != NULL) {
+    printf("%d \n", temp->data);
+    temp = temp->ptr;
+  }
+}
+void deletestart() {
+  if (head == NULL) {
+    printf("list empty");
+    return;
+  }
+  struct Node *temp = head;
+
+  head = temp->ptr;
+  free(temp);
+}
+void deletelast() {
+  if (head == NULL) {
+    printf("list empty");
+    return;
+  } else {
+    struct Node *temp = head;
+    struct Node *prev = NULL;
+    while (temp->ptr != NULL) {
+      prev = temp;
+      temp = temp->ptr;
+    }
+    prev->ptr = NULL;
+    free(temp);
+  }
+}
+
+void deletex(int x) {
+  if (head == NULL) {
+    printf("list empty");
+    return;
+  } else {
+    struct Node *temp = head;
+    struct Node *prev = NULL;
+    int k = 0;
+    while (temp->ptr != NULL && k < x - 1) {
+      prev = temp;
+      temp = temp->ptr;
+      k++;
+    }
+    // If x is beyond the last node
+    if (temp == NULL) {
+      printf("Position %d not found\n", x);
+      return;
+    }
+    prev->ptr = temp->ptr;
+    free(temp);
+  }
+}
+int main() {
+  struct Node *first = createNode(5);
+  insertstart(5, first);
+  display();
+  struct Node *second = createNode(6);
+  insertend(6, second);
+  display();
+  deletelast();
+  display();
+}
diff --git a/poly.c b/poly.c
new file mode 100644
index 0000000..884d19b
--- /dev/null
+++ b/poly.c
@@ -0,0 +1,57 @@
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+typedef struct {
+  int top;
+  int capacity;
+  char *array;
+} stack;
+
+stack *createStack(int c) {
+  stack *Stack = (stack *)malloc(sizeof(stack));
+  if (!Stack) {
+    return NULL;
+  }
+  Stack->capacity = c;
+  Stack->top = -1;
+  Stack->array = (char *)malloc(Stack->capacity);
+  if (!Stack->array) {
+    free(Stack);
+    return NULL;
+  }
+  return Stack;
+}
+
+bool isfull(stack *s) { return s->top == s->capacity - 1; }
+bool isempty(stack *s) { return s->top == -1; }
+
+int push(stack *s, char v) {
+  if (isfull(s)) {
+    printf("stack overflow");
+    return -1;
+  }
+  s->array[++s->top] = v;
+  return s->top;
+}
+int pop(stack *s) {
+  if (isempty(s)) {
+    printf("empty");
+    return -1;
+  }
+  return s->array[s->top--];
+}
+
+void display(stack *s) {
+  for (int i = 0; i <= s->top; i++) {
+    printf("%c", s->array[i]);
+  }
+}
+
+int main() {
+  stack *ms = createStack(3);
+
+  push(ms, 'a');
+  push(ms, 'b');
+  display(ms);
+}
diff --git a/stack.c b/stack.c
new file mode 100644
index 0000000..d2c8d87
--- /dev/null
+++ b/stack.c
@@ -0,0 +1,114 @@
+#include <ctype.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+typedef struct {
+  char key;
+} element;
+element stack[100];
+int top = -1;
+bool isfull() {
+  if (top == 99) {
+    return true;
+  }
+  return false;
+}
+bool isempty() {
+  if (top < 0) {
+    return true;
+  }
+  return false;
+}
+
+void push(char key) {
+  if (isfull()) {
+    printf("stack overflow \n");
+    return;
+  }
+  stack[++top].key = key;
+}
+
+char pop() {
+  if (isempty()) {
+    printf("staxk is empyyt");
+    return '\0';
+  }
+  return stack[top--].key;
+}
+
+int precedence(char op) {
+  switch (op) {
+  case '^':
+    return 3;
+  case '*':
+  case '/':
+    return 2;
+  case '+':
+  case '-':
+    return 1;
+  default:
+    return 0;
+  }
+}
+bool isRight(char op) {
+  if (op == '^') {
+    return true;
+  }
+  return false;
+}
+char peek() {
+  if (isempty()) {
+    printf("stack is empty");
+  }
+  return stack[top].key;
+}
+
+int main() {
+  char infix[100];
+  char postfix[100];
+  printf("enter infix\n");
+  scanf("%s", infix);
+
+  int k = 0;
+  int i = 0;
+
+  while (infix[i] != '\0') {
+    char current = infix[i];
+
+    if (isalpha(current)) {
+      postfix[k++] = current;
+    } else if (current == '(') {
+      push(current);
+    } else if (current == ')') {
+      while (!isempty() && peek() != '(') {
+        postfix[k++] = pop();
+      }
+      if (!isempty() && peek() == '(') {
+        pop(); // Remove '(' from stack
+      }
+    } else { // Operator
+      int currPrec = precedence(current);
+      while (!isempty() && peek() != '(') {
+        char topOp = peek();
+        int topPrec = precedence(topOp);
+
+        if (topPrec > currPrec || (topPrec == currPrec && !isRight(current))) {
+          postfix[k++] = pop();
+        } else {
+          break;
+        }
+      }
+      push(current);
+    }
+    i++;
+  }
+
+  while (!isempty()) {
+    postfix[k++] = pop();
+  }
+
+  postfix[k] = '\0';
+  printf("Postfix: %s\n", postfix);
+
+  return 0;
+}