Reverse Words in a String when . comes

Reverse Words in a String when . comes

  June 08, 2017    

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Problem : Reverse String whenever "." is encountered.

Here we are separating string to charArray and then we are checking whenever . found we are pushing string to stack and making string as empty and at last we are printing whole stack.

Ex : Input : i.am.happyOutput : happy.am.i

import java.util.*;
import java.lang.*;
import java.io.*;
class GFG
 {
public static void main (String[] args)
{
Scanner ab=new Scanner(System.in);
int t=ab.nextInt();
while(t-->0)
{
   String str2=ab.next();
   char arr[]=str2.toCharArray();
   Stack<String> stack=new Stack<String>();
   String str=new String();
   for(int i=0;i<arr.length;i++)
   {
       if(arr[i]!='.')
       str=str+arr[i];
       else if(arr[i]=='.')
       {
            str=str+arr[i];
           stack.push(str);
           str="";
       }
       if(i==arr.length-1)
       {
           str=str+".";
           stack.push(str);
       }
       
   }
  String temp=new String();
   while(stack.empty()!=true)
   {
       temp=temp+stack.pop();
   }
   temp=temp.substring(0,temp.length()-1);
   System.out.println(temp);
}
}
}