백준 1339번: 단어 수학

문제 출처: https://www.acmicpc.net/problem/1339

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
 
public class Main {
    
    public static void main(String[] args) throws NumberFormatException, IOException {
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        int N = Integer.parseInt(reader.readLine());
        
        String[] inputArr = new String[N];
        for(int i=0 ; i<N ; i++)
            inputArr[i] = reader.readLine();
        
        ArrayList<Character> alphabet = new ArrayList<>();
        ArrayList<Integer> number = new ArrayList<>();
        
        for(int i=0 ; i<N ; i++){
            String str = inputArr[i];
            for(int j=0 ; j<str.length() ; j++){
                if(!alphabet.contains(str.charAt(j))){
                    alphabet.add(str.charAt(j));
                    number.add((int)Math.pow(10, str.length()-j-1));
                }
                else{
                    int index = alphabet.indexOf(str.charAt(j));
                    number.set(index, number.get(index) + (int)Math.pow(10, str.length()-j-1));
                }
            }
        }
        
        int result = 0;
        int n = 9;
        
        while(!number.isEmpty()){
            int max = 0;
            int index = 0;
            
            for(int i=0 ; i<number.size() ; i++){
                if(max < number.get(i)){
                    max = number.get(i);
                    index = i;
                }
            }
            result += max * n--;
            number.remove(index);
        }
        
        System.out.println(result);
    }
}