Java语言基础训练
作者:互联网
写一个程序,在main方法里面定义一个数组,输出排序前的数组,将数组中的元素从小到大进行排序,输出排序后的数组。
package ZUOYE;
import java.util.Scanner;
public class A1 {
public static void QuickSort(int num[],int n){
int i,j,temp;
for(i = 0;i < n;i ++){
for(j = i + 1;j < n;j ++)
if(num[i] > num[j]){
temp = num[i];
num[i] = num[j];
num[j] = temp;
}
}
}
public static void QuickSort(double num[],int n){
int i,j;
double temp;
for(i = 0;i < n;i ++){
for(j = i + 1;j < n;j ++)
if(num[i] > num[j]){
temp = num[i];
num[i] = num[j];
num[j] = temp;
}
}
}
public static void main (String args[ ]) {
int n,i,m;
Scanner reader = new Scanner(System.in);
System.out.println("要输入的元素数量为(数量少于10):");
n = reader.nextInt();
System.out.println("要输入的元素是否有小数(有则为1,无则为2):");
m = reader.nextInt();
if(m == 1){
double[] num;
num = new double[10];
System.out.printf("请输入%d个元素:\n",n);
for(i = 0;i < n; i ++)
num[i] = reader.nextDouble();
System.out.println("排序前的元素数组为:");
for(i = 0;i < n; i ++)
System.out.printf(num[i] + " ");
QuickSort(num,n);
System.out.println("\n排序后的元素数组为:");
for(i = 0;i < n;i ++)
System.out.printf(num[i] + " ");
}
else if(m == 2){
int[] num;
num = new int[10];
System.out.printf("请输入%d个元素:\n",n);
for(i = 0;i < n; i ++)
num[i] = reader.nextInt();
System.out.println("排序前的元素数组为:");
for(i = 0;i < n; i ++)
System.out.printf(num[i] + " ");
QuickSort(num,n);
System.out.println("\n排序后的元素数组为:");
for(i = 0;i < n;i ++)
System.out.printf(num[i] + " ");
}
}
}
写一个方法,用来计算三角形的面积(参数为三个边长,实型,由键盘输入,面积计算用海伦公式:,p为三角形的半周长,使用方法Math.sqrt(),请查询JDK帮助文档,java.lang.Math类里面定义的方法),在main方法里面调用该方法,输出面积计算的结果。
package ZUOYE;
import java.lang.Math;
import java.util.Scanner;
public class A1 {
public static double Triang(double length,double width,double height){
double p = (length + width + height)/2;
return Math.sqrt(p * (p - length) * (p - width) * (p - height));
}
public static void main (String args[ ]) {
Scanner reader = new Scanner(System.in);
double length;
double width;
double height;
System.out.println("请分别输入三角形的长,宽,高:");
length = reader.nextDouble();
width = reader.nextDouble();
height = reader.nextDouble();
System.out.println("三角形的面积为:" + Triang(length,width,height));
}
}
使用一个二维数组存放如下图形的字符
*
package ZUOYE;
import java.lang.Math;
import java.util.Scanner;
public class A1 {
public static void main (String args[ ]) {
int row = 0;
int line = 0;
int m = 0;
char[][] s = {{'*'},{'*','*','*'},{'*','*','*','*','*'},{'*','*','*','*','#','*','*'}};
for(int i = 0;i < s.length;i ++)
for(int j = 0;j < s[i].length;j ++)
if(s[i][j] == '#'){
row = i;
line = j;
m = 1;
}
if(m == 1)
System.out .println ("#的位置下标为" + "[" + row + "]" + "["+ line + "]" );
else
System.out .println ("#不在该图形里!");
}
}
* * *
* * * * *
* * * * # * *
找到字符#,并打印出它在二维数组中的下标。
标签:Java,语言,int,double,System,++,基础训练,num,out 来源: https://blog.csdn.net/ywd171/article/details/121526668