一、输入输出
1、输入圆的半径,计算并输出圆的周长和面积:
- import java.util.Scanner;
- public class zuoye01_circle {
- public static void main(String[] args) {
- Scanner sc = new Scanner(System. in ); //实例化输入
- System.out.print("请输入圆的半径:");
- double r = sc.nextDouble(); //接收输入的值,并赋值给r
- double zhouchang = 2 * Math.PI * r;
- double mianji = Math.PI * Math.pow(r, 2);
- System.out.println("半径为" + r + "的圆的周长是:" + zhouchang);
- System.out.println("半径为" + r + "的圆的面积是:" + mianji);
- }
- }
二、if 语句
2、控制台输入年龄,根据年龄输出不同的提示
- import java.util.Scanner;
- public class zuoye02_nianlingpanduan {
- public static void main(String[] args) {
- for (int i = 0; i < 1; i++) {
- Scanner sc = new Scanner(System. in );
- System.out.print("请输入您的年龄:");
- int age = sc.nextInt();
- if (age > 0 && age < 135) {
- if (age < 18) {
- System.out.println("您还未成年!");
- } else if (age < 60) {
- System.out.println("您是成年人!");
- } else {
- System.out.println("您是老年人!");
- }
- } else {
- System.out.println("您输入的年龄不对!只能输入1到135之内的数!");
- i--;
- }
- }
- }
- }
三、循环语句
1、一张纸的厚度大约是 0.08mm,对折多少次之后能达到珠穆朗玛峰的高度(8848.13 米)?
- public class zuoye03_zhedie {
- public static void main(String[] args) {
- double zhi = 0.08;
- for (int i = 1; i > 0; i++) {
- zhi *= 2;
- if (zhi >= 8848130) {
- System.out.println("折叠了" + i + "次,超过了珠峰高度");
- break;
- }
- }
- }
- }
2、计算 5 的阶乘 5! 的结果是?
public class zuoye04_jiecheng {
public static void main(String[] args){
int s=1;
for(int i=1;i<=5;i++){
s*=i;
}
System.out.println("5 的阶乘是:"+s);
}
}
3、计算 1+1/2!+1/3!+1/4!+...1/20!=
- public class zuoye05_jiechengqiuhe {
- public static void main(String[] args) {
- double sum = 0;
- for (int i = 1; i <= 20; i++) {
- double s = 1;
- for (int j = 1; j <= i; j++) {
- s *= j;
- }
- sum += (1 / s);
- }
- System.out.println("结果是:" + sum);
- }
- }
4、打印出所有的 "水仙花数",所谓 "水仙花数" 是指一个三位数,其各位数字立方和等于该数本身。例如:153 是一个 "水仙花数",因为 153=1 的三次方+5 的三次方+3 的三次方。
- public class zuoye06_shuixianhuashu {
- public static void main(String[] args) {
- for (int i = 100; i <= 999; i++) {
- int a = i / 100;
- int b = (i % 100) / 10;
- int c = (i % 100) % 10;
- if (Math.pow(a, 3) + Math.pow(b, 3) + Math.pow(c, 3) == i) {
- System.out.println(i);
- }
- }
- }
- }
6、我国古代数学家张邱建在《算经》中出了一道 "百钱买百鸡" 的问题,题意是这样的:5 文钱可以买一只公鸡,3 文钱可以买一只母鸡,1 文钱可以买 3 只雏鸡。现在用 100 文钱买 100 只鸡,那么各有公鸡、母鸡、雏鸡多少只?请编写程序实现。
- public class zuoye07_baiqianbaiji {
- public static void main(String[] args) {
- int a,
- b,
- c;
- int i = 0;
- for (a = 0; a <= 20; a++) {
- for (b = 0; b <= 33; b++) {
- for (c = 0; c <= 100; c++) {
- if (c % 3 == 0 && (5 * a + 3 * b + c / 3) == 100 && (a + b + c) == 100) {
- i++;
- System.out.println("第" + i + "种买法:" + a + "只公鸡," + b + "只母鸡," + c + "只小鸡。");
- continue;
- }
- }
- }
- }
- }
- }
7、这是经典的 "百马百担" 问题,有一百匹马,驮一百担货,大马驮 3 担,中马驮 2 担,两只小马驮 1 担,问有大,中,小马各几匹?
- public class zuoye08_baimabaidan {
- public static void main(String[] args) {
- int a,
- b,
- c;
- int i = 0;
- for (a = 0; a <= 33; a++) {
- for (b = 0; b <= 50; b++) {
- for (c = 0; c <= 100; c++) {
- if ((a + b + c) == 100 && c % 2 == 0 && (3 * a + 2 * b + c / 2 == 100)) {
- i++;
- System.out.println("第" + i + "驼法:" + a + "只大马," + b + "只中马," + c + "只小马。");
- }
- }
- }
- }
- }
- }
8、控制台输出九九乘法表
- public class zuoye09_chengfabiao {
- public static void main(String[] args) {
- for (int i = 1; i <= 9; i++) {
- for (int j = 1; j <= i; j++) {
- System.out.print(j + "x" + i + "=" + (i * j) + "\t");
- }
- System.out.println();
- }
- }
- }
9、控制台输出三角形和菱形
- public class zuoye10_sanjiaoxing {
- public static void main(String[] args) {
- for (int i = 1; i <= 5; i++) {
- for (int j = 1; j <= i; j++) {
- System.out.print("★" + " ");
- }
- System.out.println();
- }
- }
- }
- public class zuoye11_lingxing {
- public static void main(String[] args) {
- for (int i = 0; i <= 5; i++) {
- for (int k = 0; k <= 5 - i; k++) {
- System.out.print(" ");
- }
- for (int j = 0; j <= 2 * i; j++) {
- System.out.print("*");
- }
- System.out.println();
- }
- for (int i = 1; i <= 5; i++) {
- for (int k = 1; k <= i + 1; k++) {
- System.out.print(" ");
- }
- for (int j = 1; j <= 11 - 2 * i; j++) {
- System.out.print("*");
- }
- System.out.println();
- }
- }
- }
PS: 菱形和三角形画一起:
- public class zuoye12_huatu {
- public static void main(String[] args) {
- for (int i = 0; i <= 5; i++) {
- for (int j = 0; j <= 6 - i; j++) {
- System.out.print("*");
- }
- for (int k = 0; k <= 2 * i; k++) {
- System.out.print("#");
- }
- for (int j = 0; j <= 6 - i; j++) {
- System.out.print("*");
- }
- System.out.println();
- }
- for (int i = 1; i <= 5; i++) {
- for (int j = 1; j <= i + 2; j++) {
- System.out.print("*");
- }
- for (int j = 1; j <= 11 - 2 * i; j++) {
- System.out.print("#");
- }
- for (int j = 1; j <= i + 2; j++) {
- System.out.print("*");
- }
- System.out.println();
- }
- }
- }
来源: http://www.cnblogs.com/jingzhenhua/p/5866357.html