Added menu driven program for linkedlist

Algorithms/sorting/quickSort_3partition.py

@@ -0,0 +1,36 @@
+# Uses python3
+import sys
+import random
+
+def partition3(a, l, r):
+    x=a[l]
+    m1=l
+    m2=l
+    for i in range(l + 1, r + 1):
+        if a[i] < x:
+            a[i], a[m1] = a[m1], a[i]
+            a[i], a[m2+1] = a[m2+1], a[i]
+            m1 += 1
+            m2 += 1
+        elif a[i] == x:
+            a[i], a[m2+1] = a[m2+1], a[i]
+            m2 += 1
+    return (m1,m2)
+
+def randomized_quick_sort(a, l, r):
+    if l >= r:
+        return
+    k = random.randint(l, r)
+    a[l], a[k] = a[k], a[l]
+    #use partition3
+    m1,m2 = partition3(a, l, r)
+    randomized_quick_sort(a, l, m1 - 1);
+    randomized_quick_sort(a, m2 + 1, r);
+
+
+n=int(input())
+lst=list(map(int,input().split()))
+randomized_quick_sort(lst,0,n-1)
+lst=list(map(str,lst))
+st=" "
+print(st.join(lst))

Data Structures/LInkedList/headnode-linkedlist.c

@@ -0,0 +1,264 @@
+//Menu driven program for linkedlist with headnode 
+//implementation of different funtions
+
+#include<stdio.h>
+#include<stdlib.h>
+
+struct Node
+{
+    int data;
+    struct Node* next;
+};
+typedef struct Node node;
+
+struct headnode
+{
+    node* start;
+    node* end;
+};
+typedef struct headnode head;
+
+void Insert_beginning(head* h,int x)
+{
+    node* q;
+    q=(node*)malloc(sizeof(node));
+    q->data=x;
+    if(h->start==NULL)
+    {
+        q->next=h->start;
+        h->start=q;
+        h->end=q;
+    }
+    else
+    {
+        q->next=h->start;
+        h->start=q;  
+    }
+}
+
+void Insert_End(head* h,int x)
+{
+    node* q;
+    q=(node*)malloc(sizeof(node));
+    q->data=x;
+    q->next=NULL;
+    if(h->start==NULL)
+    {
+        h->start=q;
+        h->end=q;
+    }
+    else
+    {
+        h->end->next=q;
+        h->end=q;
+    }
+}
+
+void Display(head h)
+{
+    if(h.start==NULL) printf("List is empty\n");
+    else
+    {
+        while(h.start!=NULL)
+        {
+            printf("%d  ",h.start->data);
+            h.start=h.start->next;
+        }
+        printf("\n");
+    }
+}
+
+void Insert_afelement(head* h,int a,int n)
+{
+    node* q;
+    node* p;
+    q=(node*)malloc(sizeof(node));
+    q->data=a;
+    if(h->start==NULL) printf("List is Empty\n\n");
+    else
+    {
+        p=h->start;
+        while(p->data!=n && p->next!=NULL)
+        {
+            p=p->next;
+        }
+        if(p==h->end)
+        {
+           q->next=p->next;
+           p->next=q;
+           h->end=q;   
+        }
+        else if(p->data==n)
+        {
+            q->next=p->next;
+            p->next=q;
+        }
+    }
+}
+
+void Delete(head* h,int a)
+{
+    node* p;
+    node* q;
+    q=h->start;
+    while(q->data!=a && q->next!=NULL)
+    {
+        p=q;
+        q=q->next;
+    }
+    if(q==h->end && q->data==a)
+    {
+        p->next=q->next;
+        h->end=p;
+        free(q);
+    }
+    else if(q->next!=NULL)
+    {
+        if(q==h->start)
+        {
+            h->start=q->next;
+        }
+        else
+        {
+            p->next=q->next;
+        }
+        free(q);
+    }
+    else printf("Element is not Present in List\n");
+}
+
+int Count_node(head* h)
+{
+    int Count=0;
+    node* p=h->start;
+    while(p!=h->end)
+    {
+        Count++;
+        p=p->next;
+    }
+    return ++Count;
+}
+int Maximum(head* h)
+{
+    int max=-100000;
+    node* p=h->start;
+    while(p!=NULL)
+    {
+        if(max<p->data) max=p->data;
+        p=p->next;
+    }
+    return max;
+}
+
+int Minimum(head* h)
+{
+    int min=100000;
+    node* p=h->start;
+    while(p!=NULL)
+    {
+        if(min > p->data) min=p->data;
+        p=p->next;
+    }
+    return min;
+}
+
+int Search(head* h,int a)
+{
+    node* p;
+    p=h->start;
+    int count=1;
+    while(p!=NULL && p->data!=a)
+    {
+        p=p->next;
+        count++;
+    }
+    if(p!=NULL) return count;
+    else return 0;
+}
+
+int main()
+{
+    head h;
+    int n,a,b;
+    h.start=NULL;
+    h.end=NULL;
+    while(1)
+    {
+        printf("Enter 1 to Insert at Beginning\n");
+        printf("Enter 2 to Insert at End\n");
+        printf("Enter 3 to Insert After an element\n");
+        printf("Enter 4 to Delete a node\n");
+        printf("Enter 5 to Display List\n");
+        printf("Enter 6 to Count Nodes\n");
+        printf("Enter 7 to Find Maximum\n");
+        printf("Enter 8 to Find Minimum\n");
+        printf("Enter 9 to Search value\n");
+        printf("Enter 10 to Exit\n");
+        scanf("%d",&n);
+        switch(n)
+        {
+            case 1:
+            {
+                printf("Enter value to Insert\n");
+                scanf("%d",&a);
+                Insert_beginning(&h,a);
+                break;
+            }
+            case 2:
+            {
+                printf("Enter value to Insert\n");
+                scanf("%d",&a);
+                Insert_End(&h,a);
+                break;
+            }
+            case 3:
+            {
+                printf("Enter value to Insert and element after which value is to be Inserted\n");
+                scanf("%d%d",&a,&b);
+                Insert_afelement(&h,a,b);
+                break;
+            }
+            case 4:
+            {
+                printf("Enter value to Delete\n");
+                scanf("%d",&a);
+                Delete(&h,a);
+                break;
+            }
+            case 5:
+            {
+                Display(h);
+                printf("\n");
+                break;
+            }
+            case 6:
+            {
+                printf("Number of nodes %d\n\n",Count_node(&h));
+                break;
+            }
+            case 7:
+            {
+                if(h.start==NULL) printf("List is Empty\n");
+                else printf("Maximum number is %d\n\n",Maximum(&h));
+                break;
+            }
+            case 8:
+            {
+                if(h.start==NULL) printf("List is Empty\n");
+                else printf("Minimum number is %d\n\n",Minimum(&h));
+                break;
+            }
+            case 9:
+            {
+                printf("Enter value to Search\n");
+                scanf("%d",&a);
+                b=Search(&h,a);
+                if(b) printf("Number is Present at %d node\n\n",b);
+                else printf("Not Present\n\n");
+                break;
+            }
+            case 10: return 0;
+            default : printf("Enter valid choice\n\n");
+        }
+    }
+}