Java基础语法n

BK      分段函数（SDUT 2257）

import java.util.*;
public class Main{
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
             double n;
                int t;
             while(sc.hasNext()) {
                 t=sc.nextInt();
                 for(int i=0;i<t;i++) {
                 n=sc.nextDouble();
                 System.out.printf("%.2f\n",f(n));}
             }
        }
    public static double f(double n){
       if(n==0) return 0;
       else if(n>=10)return n*n;
       else if(n<0) return -1*n+Math.sin(n);
       else return Math.log(n)/Math.log((double)2);
    }
}

BL      C/C++程序训练6---歌德巴赫猜想的证明（SDUT 1136）

import java.util.*;
public class Main{
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n;
        n = sc.nextInt();
        for(int i = 2; i <= n; i ++)
        {
            if(prime(i)==1 && prime(n-i)==1) {
                System.out.printf("%d=%d+%d\n",n,i,n-i);
                break;
            }
        }
    }
    public static int prime(int n)
    {
        if(n == 0 || n == 1) return 0;
        for(int i = 2; i <= (int)Math.sqrt((double)n); i ++)
        {
            if(n % i == 0) return 0;
        }
        return 1;
    }
}

BM     C语言实验——计算1到n的和（循环结构）（SDUT 1120）

import java.util.*;

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

BN      数列求和(SDUT1134)

import java.util.*;

public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int a, n;
    a = sc.nextInt();
    n = sc.nextInt();
    int ans = 0, sum = 0;
    sum = a;
    for (int i = 0; i < n; i++) {
      ans += sum;
      sum *= 10;
      sum += a;
    }
    System.out.println(ans);
  }
}

BO     C语言实验——大小写转换（SDUT 1168）

import java.util.*;

public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    String str;
    str = sc.nextLine();
    int len = str.length();   // 字符串长度
    for(int i = 0; i < len; i ++)  // 字符串单个字符引用
    {
      char op = str.charAt(i);
      if(op>='a'&&op<='z')System.out.print((char)(op-32));  
      else if(op>='A'&&op<='Z')System.out.print((char)(op+32));
      else System.out.print(op);
    }
    
  }
}

BP      C语言实验——最小公倍数和最大公约数（SDUT 1181）

import java.util.*;

public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int n, m;
    n = sc.nextInt();
    m = sc.nextInt();
    int ans1, ans2;
    ans2 = gcd(n, m);
    ans1 = n * m / ans2;
    System.out.println(ans1 + " " + ans2);
  }

  public static int gcd(int x, int y) {
    return (y == 0) ? x : gcd(y, x % y);
  }
}

BQ         成绩评估（SDUT 1222）

import java.util.*;

public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int n, f = 0;
    while(sc.hasNext())
    {
      f = 0;
      n = sc.nextInt();
      if(n>=90&&n<=100)f=1;
      else if(n>=80&&n<=89)f=2;
      else if(n>=70&&n<=79)f=3;
      else if(n>=60&&n<=69)f=4;
      else if(n>=0&&n<=59)f=5;
      else f = 0;
      if(f==0)System.out.println("Score is error!");
      else System.out.println((char)('A' + f - 1));
    }
  }
}

字符的变化（SDUT 3272）

package kk;

import java.util.Scanner;

public class Main {
    public static void main(String[] args){
      Scanner sc = new Scanner(System.in);
      String str = sc.nextLine();
      int n;
      n = sc.nextInt();
      n %= 26;
      int len = str.length();
      for(int i = 0; i < len; i ++)
      {
        char op = str.charAt(i);
        if((char)(op+n) > 'z'){
          System.out.print((char)(op+n-26));
        }
        else System.out.print((char)(op+n));
      }
      System.out.println("");
    }
}

LCM的个数(SDUT 3275)