백준[Java] 11021번 A+B-7

https://www.acmicpc.net/problem/11021

11021번: A+B - 7

문제풀이 1

import java.util.Scanner;
public class _11021_1 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        int T = sc.nextInt();

        for (int i = 1; i <= T; i++) {
            int A = sc.nextInt();
            int B = sc.nextInt();

            System.out.printf("Case #%d: %d%n", i, A+B);
        }
        sc.close();
    }
}

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문제풀이 2

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

public class _11021_2 {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

        int T = Integer.parseInt(br.readLine());

        for (int i = 1; i <= T; i++) {
            StringTokenizer st = new StringTokenizer(br.readLine(), " ");
            int A = Integer.parseInt(st.nextToken());
            int B = Integer.parseInt(st.nextToken());

            System.out.printf("Case #%d: %d%n", i, A+B);
        }
        br.close();
    }
}

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문제풀이 3

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

public class _11021_3 {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

        int T = Integer.parseInt(br.readLine());

        StringTokenizer st;
        for (int i = 1; i <= T; i++) {
            st = new StringTokenizer(br.readLine(), " ");
            System.out.println("Case #" + i + ": "
                    +(Integer.parseInt(st.nextToken())
                    +Integer.parseInt(st.nextToken())));
        }
        br.close();
    }
}

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문제풀이 4

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

public class _11021_4 {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

        int T = Integer.parseInt(br.readLine());

        StringBuilder sb = new StringBuilder();
        StringTokenizer st;

        for (int i = 1; i <= T; i++) {
            st = new StringTokenizer(br.readLine(), " ");
            sb.append("Case #").append(i).append(": ")
                    .append(Integer.parseInt(st.nextToken())
                            +Integer.parseInt(st.nextToken())).append('\n');
            // sb.append("Case #"+ i + ": " + (Integer.parseInt(st.nextToken())+Integer.parseInt(st.nextToken())) + "\n" );
        }
        br.close();
        System.out.println(sb);
    }
}

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문제풀이 5

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.util.StringTokenizer;

public class _11021_5 {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));

        int T = Integer.parseInt(br.readLine());

        StringTokenizer st;
        for (int i = 1; i <= T; i++) {
            st = new StringTokenizer(br.readLine(), " ");
            bw.write("Case #"+i+": ");
            bw.write(Integer.parseInt(st.nextToken())
                    +Integer.parseInt(st.nextToken())+"\n");
        }
        br.close();
        bw.flush();
        bw.close();
    }
}

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문제풀이 6

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

public class _11021_6 {
    public static void main(String args[]) throws IOException {

        BufferedReader br= new BufferedReader(new InputStreamReader(System.in));

        int T = Integer.parseInt(br.readLine());

        StringBuilder sb = new StringBuilder();
        for (int i = 1; i <= T; i++) {
            String str = br.readLine();
            sb.append("Case #").append(i).append(": ")
                    .append(str.charAt(0)-'0'+str.charAt(2)-'0').append('\n');
        }
        System.out.println(sb);
    }
}

 

입력에서 A 와 B 의 범위는 0 초과 10 미만 = 즉 1~9 사이

A와 B는 한 자릿수만 입력받기 때문에 문자열로 입력받을시 공백이 들어가는 위치는 언제나 고정됨

문자열의 특정 위치의 문자를 반환해주는 charAt() 사용 -> StringTokenizer 객체를 계속 생성하지 않아도 되기에 시간이 더욱 단축 

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