利用Java语言打印具有"*"号的等边三角形
/***求一个三角形*/import java.util.Scanner;import java.util.regex.Pattern;import java.util.regex.Matcher;public class Triangle { public static void dis_second() { Scanner sc = new Scanner(System.in); //接受控制台输入数据 String s = sc.nextLine(); Pattern p = Pattern.compile("^[1-9]{1}[0-9]*"); //正则表达式，匹配只能输入正数 Matcher m = p.matcher(s); if (!m.matches()) { s = "1"; } Integer a = new Integer(s); //将字符串转换为数字 if (a % 2 != 0) { int b = 0; //初始预先设置每行显示"*"的数目 int c = 0; //初始预先设置每行的空格数目 int n = 1; while (n <= (a / 2 + 1)) { b = 2 * n - 1; c = (a - b) / 2; int d = 0; int e = 0; while (d < c) { //循环打印空格 System.out.print(" "); d++; } while (e < b) { //循环打印"*" System.out.print("*"); e++; } System.out.println(); n++; } } } public static void main(String[] args) { dis_second(); }}