Kwonkyu

	private void writeJsonOnResponse(
		Object value,
		HttpServletResponse response
	) throws IOException {
		String failJsonResponse = objectMapper.writeValueAsString(value);
		response.setContentType(MediaType.APPLICATION_JSON_VALUE);
		PrintWriter writer = response.getWriter();
		writer.write(failJsonResponse);
		writer.flush();
	}

Kwonkyu

public class FieldErrorDetail {
    private String rejectedField;
    private String cause;
}

Kwonkyu

@Bean
public CorsFilter corsFilter() {
	UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
	CorsConfiguration corsConfiguration = new CorsConfiguration();
	corsConfiguration.setAllowCredentials(true);
	corsConfiguration.addAllowedOriginPattern("*");
	corsConfiguration.addAllowedHeader("*");
	corsConfiguration.addAllowedMethod("*");
	source.registerCorsConfiguration("/**", corsConfiguration);
	return new CorsFilter(source);

Kwonkyu

import lombok.AllArgsConstructor;
import lombok.Getter;

@Getter
@AllArgsConstructor
public class ApiResponse <T> {
    private final boolean success;
    private final T result;
    private final String message;

Kwonkyu

def convert(base, value):
    expr = "0123456789ABCDEF"
    result = ''
    while value >= base:
        result = expr[value % base] + result
        value = int(value / base)

    return expr[value] + result
    

Kwonkyu

class IntParser{
    public static void parse(String s){
        int i = -1;
        for(char ch: s.toCharArray()){
            if(ch >= '0' && ch <= '9'){
                if(i < 0) i = 0;
                i = i * 10 + ch - '0';
            } else {
                if(i >= 0) System.out.println(i);
                i = -1;

Kwonkyu

class SquareRootFinder {
    public static int getMaxRoot(int n){
        for(int index = n; index > 1; index--){
            double root = Math.pow(index, 0.5);
            if(root == Math.floor(root)) return index;
        }
        return -1;
    }
}

Kwonkyu

class NumberChanger {
    public static int change(int value, int position, int to) {
        if(position < 1 || value < 1 || to > 9 || to < 0) return -1;
        
        int remove = (int)Math.pow(10, position);
        int remains = (int)Math.pow(10, position - 1);
        if(remains > value) return -1;
        
        int retVal = value - value % remove + value % remains + to * remains;
        return retVal;

Kwonkyu

import requests


password = ''
password_length = -1

URL = 'https://los.rubiya.kr/chall/assassin_14a1fd552c61c60f034879e5d4171373.php'
headers = {'Content-Type': 'application/json; charset=utf-8'}
cookies = {'PHPSESSID': 'INSERT_YOUR_COOKIE_HERE'}

Kwonkyu

using System;
class HelloWorld
{
    static void Main()
    {
        String output = "1";
        for (int i = 1; i < 20; i++)
        {
            int[] typeCount = new int[10]; // from 0 to 9