洛谷官方题单[Java版题解]--【入门1】顺序结构
一.[入门1]顺序结构
1.B2002 Hello,World!
废话不多说,直接打印即可,代码如下
import java.util.*; import java.io.*; public class Main{ public static void main(String[]args ){ System.out.println(" * "); System.out.println(" *** "); System.out.println("*****"); System.out.println(" *** "); System.out.println(" *"); } }
2.B2025 输出字符菱形
废话不多说,直接打印即可,代码如下:
import java.util.*; import java.io.*; public class Main{ public static void main(String[]args ){ System.out.println(" * "); System.out.println(" *** "); System.out.println("*****"); System.out.println(" *** "); System.out.println(" *"); } }3.P1000 超级玛丽游戏
public class Main { public static void main(String[] args) { System.out.println(" ********"); System.out.println(" ************"); System.out.println(" ####....#."); System.out.println(" #..###.....##...."); System.out.println(" ###.......###### ### ###"); System.out.println(" ........... #...# #...#"); System.out.println(" ##*####### #.#.# #.#.#"); System.out.println(" ####*******###### #.#.# #.#.#"); System.out.println(" ...#***.****.*###.... #...# #...#"); System.out.println(" ....**********##..... ### ###"); System.out.println(" ....**** *****...."); System.out.println(" #### ####"); System.out.println(" ###### ######"); System.out.println("##############################################################"); System.out.println("#...#......#.##...#......#.##...#......#.##------------------#"); System.out.println("###########################################------------------#"); System.out.println("#..#....#....##..#....#....##..#....#....#####################"); System.out.println("########################################## #----------#"); System.out.println("#.....#......##.....#......##.....#......# #----------#"); System.out.println("########################################## #----------#"); System.out.println("#.#..#....#..##.#..#....#..##.#..#....#..# #----------#"); System.out.println("########################################## ############"); } }4.P1001 A+B Problem 题解
import java.util.*; import java.io.*; public class Main{ public static void main(String[] args ){ Scanner sc =new Scanner(System.in); int a=0;int b=0; a=sc.nextInt(); b=sc.nextInt(); int c=a+b; System.out.println(c); } }5.B2005 字符三角形
直接拼接即可 ,没有什么可说的,然后这里和c++不同的是,这里不能输入单个char字符
你可以使用charAt(0)直接去读取(sc.next().charAt(0));
import java.util.Scanner; public class Main { public static void main(String[] args) { Scanner sc=new Scanner(System.in); String a; a=sc.next(); System.out.println(" "+a+" "); System.out.println(" "+""+a+""+a+""+a+" "); System.out.println(""+a+""+a+""+a+""+a+""+a); } }6.P5703 【深基2.例5】苹果采购
直接两个数相乘即可
import java.util.Scanner; public class Main { public static void main(String[] args) { Scanner sc=new Scanner(System.in); int a=0;a=sc.nextInt(); int b=0;b=sc.nextInt(); System.out.println(a*b); } }7.P5704 【深基2.例6】字母转换
import java.util.Scanner; public class Main { public static void main(String[] args) { Scanner sc=new Scanner(System.in); char a=sc.next().charAt(0); //相减的原理是背后的Ascll码, //记住几个简单的即可, //a:97 A:65(相差32) //0:48 System.out.println((char)(a-32)); } }8.P5705 【深基2.例7】数字反转
当然这个写法肯定是不行的,笑哭了.对着答案编译这块.
import java.util.Scanner; public class Main { public static void main(String[] args) { Scanner sc=new Scanner(System.in); //这道题最简单的写法,就是输入单个char字符,然后反向输出即可 //123.4 4.321-->' String sc1; sc1=sc.next(); char a=sc1.charAt(0); char b=sc1.charAt(1); char c=sc1.charAt(2); char d=sc1.charAt(3); char e=sc1.charAt(4); System.out.print(e); System.out.print(d); System.out.print(c); System.out.print(b); System.out.print(a); } }9.P5706 【深基2.例8】再分肥宅水
知识点:四舍五入保留小数
//然后如果你想保留小数(),这里是四舍五入的方式 //double a=3.1415926 //可以用System.out.printf("%.2f",a),3.14import java.util.Scanner; public class Main { public static void main(String[] args) { //然后如果你想保留小数(),这里是四舍五入的方式 //double a=3.1415926 //可以用System.out.printf("%.2f",a),3.14 double a;int b; Scanner sc = new Scanner(System.in); a= sc.nextDouble(); b=sc.nextInt(); double res1=a/b; System.out.printf("%.3f",res1); System.out.println(); System.out.println(b*2); } }