DSA

Data Structures/Graph/DFS.cpp

@@ -47,14 +47,15 @@ void Graph::DFS(int s){
 }
 
 int main(){
-    Graph g(5);
+    Graph g(6);
     g.addEdge(1, 0); 
     g.addEdge(0, 2); 
     g.addEdge(2, 1); 
     g.addEdge(0, 3); 
     g.addEdge(1, 4); 
+    g.addEdge(1, 5); 
 
     g.DFS(0);
     cout<<endl;
     return 0;
-}
+}

Data Structures/Queue/Double_Ended_Queue.c

@@ -0,0 +1,110 @@
+#include<stdio.h>
+
+#define max 10
+int front = -1, rear = -1;
+int que[max];
+int is_full() {
+  if (front == max - 1 && rear == 0 || front == rear - 1) {
+    printf("Queue is full\n");
+    return 1;
+  } else
+    return 0;
+
+}
+void right_enque() {
+  if (is_full());
+  else {
+    if (front == -1) {
+      front = 0;
+      rear = 0;
+    }
+    if (front == max - 1)
+      front = 0;
+    printf("Enter a number\n");
+    int temp;
+    scanf("%d", & temp);
+    que[front++] = temp;
+  }
+}
+void left_enque() {
+  if (is_full());
+  else {
+    if (front == -1) {
+      front = 0;
+      rear = 0;
+    }
+    if (rear == 0)
+      rear = max - 1;
+    printf("Enter a number\n");
+    int temp;
+    scanf("%d", & temp);
+    que[rear--] = temp;
+  }
+}
+int is_empty() {
+  if (front == -1 || rear == -1) {
+    printf("Empty Queue\n");
+    return 1;
+  } else
+    return 0;
+}
+
+void right_deque() {
+  if (is_empty());
+  else {
+    printf("Deleted number is %d %d\n", front, que[--front]);
+
+    if (front == -1)
+      front = max - 1;
+  }
+}
+void left_deque() {
+  if (is_empty());
+  else {
+    printf("Deleted number is %d %d\n", rear, que[++rear]);
+    if (rear == max - 1)
+      rear = 0;
+  }
+}
+void display() {
+  int i;
+  if (is_empty());
+  else if (rear <= front) {
+    printf("Array is\n");
+    for (i = rear + 1; i <= front; i++)
+      printf("%d %d\n", i, que[i]);
+  } else {
+    printf("Array is\n");
+    for (i = rear + 1; i < max; i++)
+      printf("%d %d\n", i, que[i]);
+    for (i = 0; i < front; i++)
+      printf("%d %d\n", i, que[i]);
+
+  }
+}
+
+int main() {
+  int op;
+  do {
+    printf("1)right enqueue\n2)left enqueue\n3)right dequeue\n4)left dequeue\n5)display\n");
+    scanf("%d", & op);
+    switch (op) {
+    case 1:
+      right_enque();
+      break;
+    case 2:
+      left_enque();
+      break;
+    case 3:
+      right_deque();
+      break;
+    case 4:
+      left_deque();
+      break;
+    case 5:
+      display();
+      break;
+    }
+  } while (op > 0 & op < 6);
+  return 0;
+}

Data Structures/Queue/Queue.c

@@ -0,0 +1,66 @@
+#include<stdio.h>
+#define max 100
+int front=-1,rear=-1;
+int que[max];
+void enque(){
+if(rear==max-1)
+printf("Queue overflow\n");
+else {
+    if(front==-1)
+    front=0;
+    printf("Enter a number\n");
+    int temp;
+    scanf("%d",&temp);
+    que[++rear]=temp;
+}
+}
+void deque(){
+if(front==-1 or front>rear)
+printf("Queue underflow");
+else{
+    printf("Deleted number is %d\n",que[front++]);
+}
+}
+void display()
+{
+if(front==-1&&rear==-1)
+printf("Empty array");
+else if(front>-1)
+for(int i=front ;i<=rear;i++)
+printf("%d\n",que[i]);
+else
+for(int i=0 ;i<=rear;i++)
+printf("%d\n",que[i]);
+}
+void peek(){
+printf("%d\n",que[front]);
+}
+void size(){
+printf("%d\n",rear-front+1);
+}
+int main(){
+int op;
+ do{
+      printf("1)enqueue\n2)dequeue\n3)display\n4)peek\n5)size\n");
+      scanf("%d",&op); 
+  switch(op)
+  {
+  case 1:
+  enque();
+      break;
+  case 2:
+      deque();
+      break;
+  case 3:
+      printf("the stack is\n");
+      display();
+      break;
+  case 4:
+      peek();
+      break;
+ case 5:
+ size();
+  }
+}while(op>0&op<6);
+    return 0;
+}

Data Structures/Stack/Stack.c

@@ -0,0 +1,66 @@
+#include <stdio.h>
+#define max 1000
+int pt[max];
+int top=-1;
+void push(int x)
+{
+    if(top>max)
+    printf("stackoverflow");
+    else
+    {
+        pt[++top]=x;
+    }
+}
+int pop()
+{
+if(top==-1)
+printf("stackunderflow");
+else{
+printf("the number popped is");
+return pt[top--];
+}
+}
+void display()
+{
+    int i;
+    for( i=top;i>=0;i--)
+    printf("%d\n",pt[i]);
+}
+void peek()
+{
+    printf("%d\n",pt[top]);
+}
+void size()
+{
+    printf("the size of stack is %d\n",top+1);
+}
+int main() {
+    int temp;
+  int op;
+ do{
+      printf("1)push\n2)pop\n3)display\n4)peek\n5)size\n");
+      scanf("%d",&op); 
+  switch(op)
+  {
+  case 1:
+      printf("enter a number\n");
+      scanf("%d",&temp);
+      push(temp);
+      break;
+  case 2:
+      printf(" %d\n",pop());        
+      break;
+  case 3:
+      printf("the stack is\n");
+      display();
+      break;
+  case 4:
+      printf("the top number is\n");
+      peek();
+      break;
+ case 5:
+ size();
+  }
+}while(op>0&op<6);
+    return 0;
+}

Data Structures/Stack/Stack_LinkedList.c

@@ -0,0 +1,83 @@
+#include <stdio.h>
+#include <stdlib.h>
+struct node{
+    int data;
+    struct node * next;
+};
+struct node *head,*ptr;
+
+int top=-1;
+void push(int x)
+{
+ptr=head;
+struct node * newnode =(struct node *)malloc(sizeof(struct node *));
+newnode->data=x;
+newnode->next=ptr;
+head=newnode;
+top++;    
+
+}
+int pop()
+{
+if(top<0)
+printf("stackunderflow");
+else
+{
+printf("the number popped is: ");
+ptr=head;
+head=head->next;
+int v= ptr->data;
+free(ptr);
+top--;
+return v;
+}
+
+}
+void display()
+{
+    ptr=head;
+    while(ptr!=NULL)
+    {
+        printf("%d\n",ptr->data);
+        ptr=ptr->next;
+    }
+}
+void peek()
+{
+    printf("%d\n",head->data);
+}
+void size()
+{
+    printf("the size of stack is %d\n",top+1);
+}
+int main() {
+
+  int temp;
+  int op;
+ do{
+      printf("1)push\n2)pop\n3)display\n4)peek\n5)size\n");
+      scanf("%d",&op); 
+  switch(op)
+  {
+  case 1:
+      printf("enter a number\n");
+      scanf("%d",&temp);
+      push(temp);
+      break;
+  case 2:
+      printf(" %d\n",pop());        
+      break;
+  case 3:
+      printf("the stack is\n");
+      display();
+      break;
+  case 4:
+      printf("the top number is\n");
+      peek();
+      break;
+ case 5:
+ size();
+  }
+}while(op>0&op<6);
+    return 0;
+}

Data Structures/Tree/tree.cpp

@@ -13,7 +13,7 @@ struct Node{
 
 int main(){
     Node *head = new Node(10);
-    head->next = new Node(20);
+    head->next = new Node(30);
     cout<<head->data<<"->"<<head->next->data<<endl;
     return 0;
-}
+}