Infosys Problem Statement

Given a string comprised of lowercase letters in the range ascii[a-z], determine the length of the smallest substring that contains all of the letters present in the string.

For example, given the string s = dabbcabcd, the list of all characters in the string is [a, b, c, d]. Two of the substrings that contain all letters are ciabbc and abcd. The shortest substring containing all the letters is 4 characters long, abed.

Function Description Complete the function shortestSubstring in the editor below. The function must return the length of the shortest substring that contains all of the characters within s. shortestSubstring has the following parameter s: a string

Solution -> in Java

import java.io.*;
import java.math.*;
import java.security.*;
import java.text.*;
import java.util.*;
import java.util.concurrent.*;
import java.util.function.*;
import java.util.regex.*;
import java.util.stream.*;
import static java.util.stream.Collectors.joining;
import static java.util.stream.Collectors.toList;

import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
class Result {
    final static int limit = 256;
    static int error=0;
    public static int max_char(String str, int n) { 
        int count[] = new int[limit]; 
        for (int i = 0; i < n; i++) { 
            count[str.charAt(i)]++; 
        } 
        int max_distinct = 0; 
        for (int i = 0; i < limit; i++) { 
            if (count[i] != 0) { 
                max_distinct++; 
            } 
        } 
        return max_distinct; 
    } 
    public static int shortestSubstring(String s) {
    int n=s.length();
    int max = max_char(s, n);
    int minl=n;
    for (int i = 0; i <=  n; i++) { 
            for (int j = 0; j <= n; j++) { 
                String substr = null; 
                if(i<j) 
                    substr = s.substring(i, j); 
                else
                    substr = s.substring(j, i); 
                int subs_lenght = substr.length(); 
                int sub_distinct_char = max_char(substr, subs_lenght); 
                if (subs_lenght < minl && max == sub_distinct_char) { 
                    minl = subs_lenght;
                } 
            } 
        } 
        return minl; 
    } 

    public static void main(String args[]){
        Scanner in = new Scanner(System.in);
        System.out.println("Enter the String");
        String s = in.next();
        int len_str = s.length();
        for(int i = 0;i<len_str;i++)
        {
            char res = s.charAt(i);
            if(Character.isDigit(res))
            {
                error =1;
            }
               
        }
         if(error == 0)
         {
             int len_substr = shortestSubstring(s);
             System.out.println("The shortest substring length is: "+len_substr);
         }
        else
         {
             System.out.println("String Contains number");
         }
         in.close();
    }
}