CareerCup

write a shell script to append the contents of one file to another file. If any word is common in both files that need not be appended.

There is a log file with writes processes details in the below mentioned format .
---
Process_Name - RID(MB) - Time
---
It is updated every second. write bash script to report processes which is having RID greater than 30.
NB: Avoid reading the file line by line as it is very huge and updated every second

given a string, characters can be shuffled to make a paliandrome.
What is the minimum possible number of insertions to original string needed so that it will be a palindrome (after shuffling, if required).

Input

T -> number of test cases
T number of Strings in different lines

import java.util.Arrays;
import java.io.InputStreamReader;
import java.io.BufferedReader;

public class Xsquare{
	public static void main (String[] args) throws Exception{
		 BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		int limit = Integer.parseInt(br.readLine());
		
		int [] alphabets = new int[26];
		
		while(limit-- >0){
			String input = br.readLine();
			Arrays.fill(alphabets,0);
			char [] inpChar = input.toCharArray();
			int sum = 0;
			
			for (int i=0;i<input.length();i++){
					int pos = (int)inpChar[i] - (int)'a';
					alphabets[pos]+=1;
			}
			
			for(int i=0;i<26;i++){
				if(alphabets[i]%2==0)
					sum+=0;
				else
					sum+=1; 
			}
			
			if(sum<=0)
				sum=0;
			else 
				sum-=1;
			System.out.println(sum);
		}
	}
}

This is the code I submitted online. But it was not accepted as solution. What is the correct approach to this question?

There are different buildings standing close to each other. These are of same width but different height.
Suppose if rainfall happens, what will be the volume of water that get trapped on top of all these buildings together. ?

INPUT (Example)

No: of buildings : 4
heights of the buildings(in any units): 3 4 3 4