问题 1038: C语言程序设计教程（第三版）课后习题9.3

import java.util.Scanner;

public class Prog1038 {

public static void main(String[] args) {

Scanner scan = new Scanner(System.in);

double a = scan.nextInt();

double b = scan.nextInt();

double c = scan.nextInt();

double p = 0;

double s = 0;

if ((a + b) > c && (a + c) > b && (b + c) > a) {

p = (a + b + c) / 2.0;

s = Math.sqrt(p * (p - a) * (p - b) * (p - c));

String qq = String.format("%.3f", s);

System.out.println(qq);

}

}

}