백준[Java] 8393번 합

https://www.acmicpc.net/problem/8393

8393번: 합

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문제풀이 1

import java.util.Scanner;
public class _8393_1 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        int n = sc.nextInt();
        sc.close();
        int sum = 0;


        for (int i = 0; i <= n; i++) {
            sum += i;
        }
        System.out.println(sum);
    }
}

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문제풀이 2

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class _8393_2 {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

        int n = Integer.parseInt(br.readLine());
        br.close();
        int sum = 0;


        for (int i = 0; i <= n; i++) {
            sum += i;
        }
        System.out.println(sum);
    }
}

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문제풀이 3

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class _8393_3 {
    public static void main(String[] args) throws IOException {

        int n = Integer.parseInt(new BufferedReader(new InputStreamReader(System.in)).readLine());
        int sum = 0;


        for (int i = 0; i <= n; i++) {
            sum += i;
        }
        System.out.println(sum);
    }
}

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