Question

Write a java program that accepts a string from the user. List all characters in the string from lowest ASCII value to highest and output the number of occurrences for each of those characters.

Answer 1

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Summary : Firstly took string input. Than convert that string to character array and sort that character array. Now, create a hash map to take each character and it's count. Now iterate a loop and check one by one each character from character array if it is already present in hasp map than increase it's occurrence by one and if it not present than add it in hash map and put occurrence to one. Finally. print all values of hash map.

import java.io.*;
import java.util.*;

class Main {
public static void main(String[] args) {
System.out.println("Enter String");
Scanner sc = new Scanner(System.in);//Making sc an object of scanner class
String s = sc.nextLine();//Taking input
char[] ch = s.toCharArray(); //converting string to char array
Arrays.sort(ch);// sorting char array so they can be printed from smaller to biggest in ASCII value

HashMap<Character, Integer> countchar = new HashMap<Character, Integer>();/*creating a hashmap of
char and int to count occurence of each character*/
for (char c : ch) {
if (countchar.containsKey(c)) {//checking if hash map already contains character c
countchar.put(c,countchar.get(c) + 1); //if yes than increase it's count by 1
}
else {
countchar.put(c, 1); //if no than out it in hash map
}
}
//print the output
for (Map.Entry e : countchar.entrySet()) {
System.out.println(e.getKey() + " " + e.getValue());// char and it's number of occurence is printed
}

sc.close();//closing sc
}
}