Programming interview - written tests

[Anonymous_Abstract]

String a = "thinking";
String b = "guy";

a = a + b; //thinkingguy
b = a.substring(0, a.length()-b.length()); //thingking
a = a.substring(b.length()); //guy

System.out.println("a " + a);
System.out.println("b " + b);

n = n+b;
b = n.substring(0,n.length()-b.length());
n = n.substring((n.length()+b.length())-n.length(),n.length());
System.out.println("After Swap");

System.out.println("n = "+n);
System.out.println("b = "+b);

 

[Anonymous_Abstract]

Complete Code Of Merge Sort

package com.benz.test;

public class MergeAlgo {

public static void main(String[] args)
{
MergeAlgo al = new MergeAlgo();
al.algo();
}


public void algo()
{
int[] arr= {5,4,3,2,1};


arr =mergeSort(arr);

for(int a : arr)
{
System.out.print(a+"\t");
}
}

public int[] mergeSort(int[] A)
{
int n = A.length;

if(n<2)
{
return A;
}else {
int mid = (n-1)/2;
int nL,nR;
nL=mid+1;
nR=n-(mid+1);

int[] left = new int[nL];
int[] right = new int[nR];



for(int i=0;i<=mid;i++)
{
left = A;

}

for(int i=mid+1;i<n;i++)
{

right[i-(mid+1)]=A;
}


int[] array = new int[A.length];

mergeSort(left);
mergeSort(right);
array = merge(left,right);

return array;
}
}

public int[] merge(int[] L,int[] R)
{
int[] A = new int[L.length+R.length];

int nL = L.length;
int nR = R.length;

int i,j,k;
i=j=k=0;

while(i<nL && j<nR)
{
if(L<=R)
{
A[k]=L;
i++;
}else
{
A[k]=R[j];
j++;
}
k +=1;
}

while(i<nL)
{
A[k]=L;
i++;
k +=1;

}

while(j<nR)
{
A[k]=R[j];
j++;
k +=1;

}

return A;

}

}

 

[Anonymous_Abstract]

Code Of Quick Sort
package com.benz.test;

public class Quick {

public int partition(int[] arr,int low,int high)
{
int pivot = high;
int l = low-1;

for(int j=low;j<=high-1;j++)
{
if(arr[j]<=arr[pivot])
{
l+=1;
swap(l,j,arr);
}
}
swap(l+1,high,arr);

return l+1;
}

public int[] swap(int x,int y,int[] A)
{
int temp = A[x];
A[x] = A[y];
A[y] =temp;

return A;
}

public void quickSort(int[] arr,int low,int high)
{
if(low>=high)
{
return;
}else {
int z = partition(arr,low,high);

quickSort(arr,low,z-1);
quickSort(arr,z+1,high);
}
}
public void show(int[] arr)
{
for(int i : arr)
{
System.out.print(i+"\t");
}
}
public static void main(String[] args)
{
Quick qu = new Quick();

int[] arr= {20,10,15,40,50,60,45};
int high = arr.length-1;
int low=0;
qu.quickSort(arr, low, high);

System.out.println("Sorted Array");
qu.show(arr);


}

}

 

[Anonymous_Abstract]

Method Create for Proper Case

package com.benz.test;

public class Reverse {

public static void main(String[] args)
{
Reverse rev=new Reverse();
String nstr = rev.toProper("hEllo WORld beNz hOW are yoU");
System.out.println(nstr);
}
public void reverse(int value)
{
int rem;
while(value>0)
{
rem = value % 10;
System.out.print(rem);
value = value/10;
}
}

public String toProper(String str)//hEllo WORld
{
if(str.trim().length()>0)
{
String newstr=null;
str =str.toLowerCase();//hello world
String[] st = str.split(" ");//hello , world
char[] ch=null;
for(String s : st)
{
ch = s.toCharArray(); //'h' 'e' 'l' 'l' 'o' , 'w' 'o' 'r' 'l' 'd'
ch[0] = Character.toUpperCase(ch[0]);//'H' ,'W'
if(newstr==null)
newstr = new String(ch);
else
newstr +=" "+ new String(ch);
}
return newstr;

}else
return str;
}
}

 

[Anonymous_Abstract]

Single Linked List In Java
package com.benz.test;

import java.util.Scanner;

class Node{
int data;
Node link;

public Node(int data,Node link)
{
this.data=data;
this.link=link;
}
}

public class SingleLinkedList {

Node root=null;
Scanner sc = null;

public SingleLinkedList()
{
sc = new Scanner(System.in);
}
public void details()
{
while(true)
{
System.out.println("1.append");
System.out.println("2.begin");
System.out.println("3.after");
System.out.println("4.delete");
System.out.println("5.display");
System.out.println("6.swap");
System.out.println("7.exit");

int ch;
System.out.println("Enter your choice");
ch = sc.nextInt();

switch(ch)
{
case 1:append();break;
case 2:begin();break;
case 3:after();break;
case 4:delete();break;
case 5:display();break;
case 6:swap();break;
case 7:System.exit(4);
default:System.out.println("Invalid Input");
}
}
}

public void append()
{
Node temp;
System.out.println("Enter a Value");
int value = sc.nextInt();
temp = new Node(value,null);

if(root==null)
{
root=temp;
}else
{
Node p;
p=root;
while(p.link != null)
{
p= p.link;
}
p.link=temp;
}
}
public void begin()
{
Node temp;
System.out.println("Enter a Value");
int value = sc.nextInt();
temp = new Node(value,null);

if(root==null)
{
root=temp;
}else {
temp.link=root;
root =temp;

}
}
public void after()
{
int loc;
System.out.println("Enter the location to add node");
loc = sc.nextInt();

if(loc>=length())
{
System.out.println("Invalid location");
System.out.println("Current node is "+length());
}else {
Node temp;
System.out.println("Enter a Value");
int value = sc.nextInt();
temp = new Node(value,null);

Node p=root;

int i=1;
while(i<loc)
{
p =p.link;
i++;
}
temp.link=p.link;
p.link=temp;
}
}

public void delete()
{
if(root==null) {
System.out.println("No nodes in the list");
}else
{
int loc;
System.out.println("Enter the location to delete node");
loc = sc.nextInt();

Node temp;

if(loc>length())
{
System.out.println("Invalid location");
System.out.println("Current node is "+length());
}else if(loc==1)
{
temp =root;
root = temp.link;
temp.link=null;
}else {
int i=1;
temp=root;
Node p;
while(i<loc-1)
{
temp=temp.link;
i++;
}
p = temp.link;
temp.link = p.link;
p.link=null;



}
}
}
public void display()
{
Node temp =root;
if(root==null)
{
System.out.println("No nodes in the list");
}else {
while(temp != null)
{
System.out.print(temp.data+"-->\t");
temp=temp.link;
}
System.out.print("\n");
}
}
public int length()
{
int len=0;
Node temp =root;
if(temp == null)
return len;
else {
while(temp !=null)
{
len +=1;
temp = temp.link;
}
return len;
}
}

public void swap()
{
Node temp = root;
if(root==null)
{
System.out.println("No nodes in the list");
}else {
int loc;
System.out.println("Enter the location to swap node");
loc = sc.nextInt();

if(loc>=length())
{
System.out.println("Invalid location");
System.out.println("Current node is "+length());
}else if(loc==1)
{
//System.out.println("Invalid Location");
Node p,q,r;
p=temp;
q=p.link;
r=q.link;

p.link=r;
q.link=p;
root =q;
}else {
Node p,q,r;
p=temp;
int i=1;
while(i<loc-1)
{
p=p.link;
i++;
}
q =p.link;
r=q.link;

q.link= r.link;
r.link=q;
p.link = r;
}
}
}
public static void main(String[] args) {

SingleLinkedList li =new SingleLinkedList();
li.details();
}

}

 

[Anonymous_Abstract]

Circular Queue in Java

package com.benz.test;

import java.util.Scanner;

public class Cqueue {


private int size;
private int rear,front;
private int[] cqueu=null;
private boolean exit=false;
Scanner sc=null;
public Cqueue(int size,int rear,int front)
{
this.size=size;
this.front=front;
this.rear=rear;
cqueu=new int[this.size];
}
public void show()
{
while(exit==false)
{
sc= new Scanner(System.in);
System.out.println("1. Enqueue");
System.out.println("2. Dequeue");
System.out.println("3. Display");
System.out.println("4. Exit");

System.out.println("Enter your choice");
int x = sc.nextInt();

switch(x)
{
case 1:System.out.println("Enter a Value");
enqueue(sc.nextInt());break;
case 2:dequeue();break;
case 3:display();break;
case 4:exit();break;
default:System.out.println("Invalid Input");break;
}
}
}
public void exit()
{

System.out.println("Program is Exited");
exit = true;

}
public void enqueue(int value)
{
if(rear==size-1 && front==0 || front==rear+1)
System.out.println("Queue is Overflow");
else if(rear==-1 && front==-1)
{
front=rear=0;
cqueu[rear]=value;
System.out.println(value +" is inserted");

}else if(rear==size-1 && front !=0)
{
rear=0;
cqueu[rear]=value;
System.out.println(value +" is inserted");
}else {
rear++;
cqueu[rear]=value;
System.out.println(value +" is inserted");

}
}
public void dequeue()
{
if(front==-1 && rear==-1)
System.out.println("Queue is Empty");
else if(front==rear)
{
int del=cqueu[front];
System.out.println(del+" is deleted");
front=rear=-1;
}else if(front==size-1)
{
int del=cqueu[front];
System.out.println(del+" is deleted");
front=0;

}else {
int del=cqueu[front];
System.out.println(del+" is deleted");
front +=1;
}
}
public void display()
{
if(rear==-1 && front==-1)
System.out.println("Queue is Empty");
else if(rear >=front)
{
for(int i=front;i<=rear;i++)
{
System.out.print(cqueu+"\t");
}
System.out.print("\n");
}else {
for(int i=front;i<size;i++)
{
System.out.print(cqueu+"\t");
}

for(int i=0;i<=rear;i++)
{
System.out.print(cqueu+"\t");
}

System.out.print("\n");
}
}
public static void main(String[] args)
{
Cqueue que= new Cqueue(6,-1,-1);
que.show();
}


}

 

[Anonymous_Abstract]

Reverse a given String in java without StringBuffer/Builder..
Intern Technical interview @ Virtusa

public static void main(String[] args) {
TestDemo td = new TestDemo();

String str = "Fuck";
str = td.reverse(str).toString();
System.out.println(str);

}

public StringBuffer reverse(String str) throws ArrayIndexOutOfBoundsException
{

char[] ch = str.toCharArray();//'F','u','c','k'
int len = ch.length;
//char[] ch2=new char[len];
StringBuffer sb = new StringBuffer();
for(int i=len-1;i>=0;i--)
{
sb.append(ch);
}

return sb;
}

 

[amilabanuka]

Reverse a given String in java without StringBuffer/Builder..
Intern Technical interview @ Virtusa

on top of
Anonymous_Abstract has given,
you can use a stack and traverse the String.

 

[OrangeHat]

print star pattern