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)