initial Commit 🎉

Author: ashiqursuperfly

ArrayList/Arraylist.cpp

@@ -0,0 +1,246 @@
+#include<iostream>
+using namespace std;
+#define LIST_INIT_SIZE 2
+#define NULL_VALUE -99999
+#define SUCCESS_VALUE 99999
+
+
+int listMaxSize;
+int * list;
+int length;
+
+
+void initializeList()
+{
+    listMaxSize = LIST_INIT_SIZE;
+    list = (int*)malloc(sizeof(int)*listMaxSize) ;
+    length = 0 ;
+}
+int getLength()
+{
+    return length;
+}
+int searchItem(int item)
+{
+    int i = 0;
+    for (i = 0; i < length; i++)
+    {
+        if( list[i] == item ) return i;
+    }
+    return NULL_VALUE;
+}
+
+int insertItem(int newitem)
+{
+    ///Add Logic to Promote clear()
+    if(list==nullptr){
+        initializeList();
+    }
+    if (length == listMaxSize)
+    {
+        int * tempList ;
+        //allocate new memory space for tempList
+        listMaxSize = 2 * listMaxSize ;
+        tempList = (int*) malloc (listMaxSize*sizeof(int)) ;
+        int i;
+        for( i = 0; i < length ; i++ )
+        {
+            tempList[i] = list[i] ; //copy all items from list to tempList
+        }
+        free(list) ; //free the memory allocated before
+        list = tempList ; //make list to point to new memory
+
+
+    }
+    list[length] = newitem ; //store new item
+    length++ ;
+    return SUCCESS_VALUE ;
+}
+
+int insertItemAt(int pos,int item)
+{
+
+
+    if(pos>=length)
+    {
+        printf("Invalid Index!\n");
+        return NULL_VALUE;
+    }
+
+        insertItem(item);
+        if (length != 1) {///swap only if
+            list[length - 1] = list[length - 1] ^ list[pos];
+            list[pos] = list[length - 1] ^ list[pos];
+            list[length - 1] = list[length - 1] ^ list[pos];
+            return SUCCESS_VALUE;
+        }
+
+}
+void shrink()
+{
+    int * tempList ;
+    listMaxSize =(int)(0.5 * listMaxSize) ;
+    tempList = (int*) malloc (listMaxSize*sizeof(int)) ;
+    int i;
+    for( i = 0; i < length ; i++ )
+    {
+        tempList[i] = list[i] ; 
+    }
+    free(list) ;
+    list = tempList ;
+}
+int deleteItemAt(int position) //version 2, do not preserve order of items
+{
+    if ( position >= length ) return NULL_VALUE;
+    list[position] = list[length-1] ;
+    length-- ;
+    if(length<=listMaxSize/2 && length>=LIST_INIT_SIZE)shrink();
+    return SUCCESS_VALUE ;
+}
+void clear()
+{
+    listMaxSize=0;
+    free(list);
+    list=nullptr;
+
+}
+void deleteAll()
+{
+    int * tempList ;
+    listMaxSize =LIST_INIT_SIZE ;
+    length=0;
+    tempList = (int*) malloc (listMaxSize*sizeof(int)) ;
+    free(list);
+    list=tempList;
+}
+int deleteItem(int item)
+{
+    int position;
+    position = searchItem(item) ;
+    if ( position == NULL_VALUE ) return NULL_VALUE;
+    deleteItemAt(position) ; ///**which Ensures shrink() to be invoked(if Necessary) since shrink() is Called inside deleteItemAt
+    return SUCCESS_VALUE ;
+}
+
+int deleteLast()
+{
+    if(length!=0) {
+        int temp=list[length-1];
+        deleteItemAt(length - 1); ///**which Ensures shrink() to be invoked(if Necessary) since shrink() is Called inside deleteItemAt
+        return temp;///promotes task 7 at ease
+    }
+    return NULL_VALUE;
+}
+void printList()
+{
+    int i;
+    for(i=0;i<length;i++)
+        printf("%d ", list[i]);
+    printf("Current size: %d, current length: %d\n", listMaxSize, length);
+}
+
+
+
+////Main Function for First 6 Tasks ////
+int main(void)
+{
+    initializeList();
+    for(int i=1;i<20;i=i+2,insertItem(i));
+    while(1)
+    {
+        printf("1. Insert new item. 2. Delete item at. 3. Delete item.\n");
+        printf("4. Insert New Item at(pos,item). 5. Print. 6.DeleteLast 7.DeleteAll 8.Clear 9.exit \n");
+
+        int ch;
+        scanf("%d",&ch);
+        if(ch==1)
+        {
+            int item;
+            scanf("%d", &item);
+            insertItem(item);
+        }
+        else if(ch==2)
+        {
+            int pos;
+            scanf("%d", &pos);
+            deleteItemAt(pos);
+        }
+        else if(ch==3)
+        {
+            int item;
+            scanf("%d", &item);
+            deleteItem(item);
+        }
+        else if(ch==4)
+        {
+            int item,pos;
+            scanf("%d%d",&pos,&item);
+            insertItemAt(pos,item);
+        }
+        else if(ch==5)
+        {
+            printList();
+        }
+        else if(ch==6)
+        {
+           deleteLast();
+        }
+        else if(ch==7) {
+            deleteAll();
+        }
+        else if(ch==8)
+        {
+            clear();
+        }
+        else if(ch==9)
+        {
+            break;
+        }
+    }
+
+}
+
+////Main Function for Task 7 ////
+/*int main()
+{
+    string s;
+    cin>>s;
+    int ans=0;
+    for(int i=0;i<s.length();i++)
+    {
+        if(s[i]-'0'>=0 && s[i]-'0'<=9)insertItem(s[i]-'0');
+        else
+        {
+            int temp2=deleteLast();
+            int temp1=deleteLast();///temp2 must be taken earlier to maintain '-' or '/' correctly
+            if(s[i]=='+')
+            {
+                 ans=temp1+temp2;
+                insertItem(ans);
+            }
+            if(s[i]=='-')
+            {
+                ans=temp1-temp2;
+                insertItem(ans);
+            }
+            if(s[i]=='*')
+            {
+                 ans=temp1*temp2;
+                 insertItem(ans);
+            }
+            if(s[i]=='/')
+            {
+                if(temp2==0)
+                {
+                    cout<<"Cant Divide by Zero!!"<<endl;
+                }
+                 else {
+                    ans = temp1 / temp2;
+                    insertItem(ans);
+                }
+            }
+        }
+    }
+    cout<<ans;
+}
+*/