Description
Please implementation the following two functions in MyTriangle.h. Note that you need not write the main() function.
/* Returns true if the sum of any two sides is
greater than the third side. */
bool isValid(double side1, double side2, double side3)
/* Returns the area of the triangle. */
double area(double side1, double side2, double side3)
The formula for computing the area is
s = (side1 + side2 + side3) / 2;
area = sqrt(s(s-side1)(s-side2)(s-side3))
Example Input1
1.0 2.0 3.0
Example Output1
Invalid!
Example Input2
3.0 4.0 5.0
Example Output2
6.00
The header files and main functions provided by the title are as follows:
#include<stdio.h>
#include "MyTriangle.h"
int main(){
double side1, side2, side3;
scanf("%lf%lf%lf", &side1, &side2, &side3);
if(isValid(side1, side2, side3)){
printf("%.2lf", area(side1, side2, side3));
}else{
printf("Invalid!");
}
return 0;
}
#include "MyTriangle.h"
#include<stdbool.h>
/* Returns true if the sum of any two sides is
greater than the third side. */
bool isValid(double side1, double side2, double side3);
/* Returns the area of the triangle. */
double area(double side1, double side2, double side3);
My code:
// Date:2020/4/3
// Author:xiezhg5
#include<stdbool.h> //bool函数包含着这个头文件中
#include<stdio.h>
#include<math.h> //一定要加这个头文件
bool isValid(double side1, double side2, double side3)
{
bool a=false; //bool类型C99标准中有
if((side1+side2>side3)&&(side1+side3>side2)&&(side2+side3>side1))
a=true;
return a;
}
double area(double side1, double side2, double side3)
{
double s=0;
if (isValid(side1, side2, side3))
{
double b=(side1+side2+side3)/2;
s=sqrt(b*(b-side1)*(b-side2)*(b-side3));
}
return s;
}
Boolean type support library
C Type support
The C programming language, as of C99, supports Boolean arithmetic with the built-in type _Bool (see _Bool). When the header <stdbool.h> is included, the Boolean type is also accessible as bool.
Standard logical operators &&, ||, ! can be used with the Boolean type in any combination.
A program may undefine and perhaps then redefine the macros bool, true and false.
Example
#include <stdio.h>
#include <stdbool.h>
int main(void)
{
bool a=true, b=false;
printf("%d\n", a&&b);
printf("%d\n", a||b);
printf("%d\n", !b);
}
Output:
0
1
1
