杭电OJ 题目(2000-2006)+答案源码记录（可提交成功）

这几天兴趣来了刚好刷一刷杭电oj，顺便分享一下答案，都是些基础题，如果有问题欢迎随时指出，会保持更新.
1000：太简单
1001:

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        int n = 0;
        int sum = 0;
        Scanner sc = new Scanner(System.in);
        while (sc.hasNextInt()) {
            n=sc.nextInt();
            for (int i = 1; i <= n; i++) {
                sum += i;
            }
            System.out.println(sum);
            //
            System.out.println();
            sum=0;
        }
        sc.close();
    }
}

1002：
格式很重要-回车一般都是用**\r\n,**所以一般我们也用这个，还要注意大数运算

import java.math.BigInteger;

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {

        BigInteger a;
        BigInteger b;
        Scanner sc = new Scanner(System.in);
        int T=0;
        T=sc.nextInt();
        for (int i = 1; i <= T; i++) {
             a=sc.nextBigInteger();
             b=sc.nextBigInteger();
             //每个实例间需要换行
             if(i==T) {
                 System.out.println("Case " + (i) + ":\r\n" + a + " + " + b + " = " + a.add(b));
             }
             else {
                 System.out.println("Case " + (i) + ":\r\n" + a + " + " + b + " = " + a.add(b)+"\r\n");
             }
        }
        sc.close();
    }
}

这里不想看英文了，开始刷中文题了哈哈
2000：

import java.util.Arrays;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner in=new Scanner(System.in);
        while(in.hasNext()){
            String charlist=in.nextLine();
            char[] chars = charlist.toCharArray();
            Arrays.sort(chars);
            for(int i=0;i<chars.length;i++){
                if(i==chars.length-1){
                    System.out.println(chars[i]);
                }
                else{
                    System.out.print(chars[i]+" ");
                }
            }
        }
        in.close();
    }
}

2001：

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        double x1 = 0, y1 = 0;
        double x2 = 0, y2 = 0;
        while (in.hasNext()) {
            x1 = in.nextDouble();
            y1 = in.nextDouble();
            x2 = in.nextDouble();
            y2 = in.nextDouble();
            System.out.println(String.format("%.2f",cau(x1,x2,y1,y2)));
        }
        in.close();
    }

    static double cau(double x1, double x2, double y1, double y2) {
        return  Math.sqrt(((x1-x2))*(x1-x2)+(y1-y2)*(y1-y2));

    }
}

2002：

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        double r=0;
        final Double pi=3.1415927;
        while (in.hasNext()) {
          r=in.nextDouble();
          System.out.println(String.format("%.3f",4*(pi)*Math.pow(r,3)/3));
        }
        in.close();
    }

}

2003:

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        while (in.hasNext()) {
            double A = in.nextDouble();
            double B = Math.abs(A);
            System.out.println((String.format("%.2f", B)));
        }
        in.close();
    }

}

2004:

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        while (in.hasNext()) {
            int score=in.nextInt();
            System.out.println(judge(score));
        }
        in.close();
    }

    static String judge(Integer score){
        if(0 <= score&&score<= 59){
            return "E";
        }
        if(60 <= score&&score<= 69){
            return "D";
        }
        if(70 <= score&&score<= 79){
            return "C";
        }
        if(80 <= score&&score<= 89){
            return "B";
        }
        if(90 <= score&&score<= 100){
            return "A";
        }
        else{
            return "Score is error!";
        }
    }

}

2005:开始陷入了判断语句过多的困境，没有想到直接定义每个月的天数然后用循环的方式

在这里import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sn = new Scanner(System.in);
        // 数组初始化 每个月的天数
        int m[] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
        while (sn.hasNext()) {
            String s = sn.nextLine();
            String[] str = s.split("/");
            int yy = Integer.parseInt(str[0]);
            int mm = Integer.parseInt(str[1]);
            int dd = Integer.parseInt(str[2]);

            int flag = 0; // 表示闰年的标记

            // 是闰年
            if (yy % 4 == 0 && yy % 100 != 0 || yy % 400 == 0) {
                flag = 1;
            }

            int ans = 0; // 定义统计天数的变量
            for (int i = 0; i < mm - 1; i++) {
                ans = ans + m[i];
            }
            ans = ans + dd;
            if (flag == 1 && mm > 2) {
                ans++;
            }
            System.out.println(ans);
        }

    }
}

2006:

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sn = new Scanner(System.in);
        int count=0;
        int result=1;
        while (sn.hasNext()) {
            count = sn.nextInt();
            int a = 0;
            try {
                for (int i = 0; i < count; i++) {
                    a = sn.nextInt();
                    if (a % 2 ==1) {
                        result = result * a;
                    }
                }
            }
            catch (RuntimeException e){
                e.printStackTrace();
            }
            finally {
                if(result==1){
                    throw new RuntimeException("请输入至少一个奇数");
                }
                System.out.println(result);
                result=1;//作初始化
            }
        }
    }
}