利用java打印正三角形_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 = pile("^[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();

}

}