C++使用用戶輸入數據爲多種功能

Question

您好我期待寫一個程序用於任意的三角形。 雖然我已經完成了我的任務的第一部分，即查找三角形是真還是假。我希望能夠使用用戶輸入的數據計算周長，然後計算三角形的面積。

但在計算周長時，它是相當龐大的數字。

This is my code so far.#include "stdafx.h" 
#include "math.h" 

    enter code here 

// ConsoleApplication6.cpp : Defines the entry point for the console application. 
// 

#include "stdafx.h" 
#include "math.h" 

/* enter three variables a, b ,c to create a triangle*/ 
int main() 
{ 
    double a; /*insert dimensions of side a*/ 
    double b; /*insert dimensions of side b*/ 
    double c; /*insert dimensions of side c*/ 
    double p; /*variable for the perimeter of a triangle*/ 
    double s; /*variable for the area of a triangle*/ 

    /* Get the user to enter the dimensions of a*/ 
    printf_s("enter the dimensions of a: "); 
    scanf_s("%d", &a);       

    /* Get the user to enter the dimensions of b*/ 
    printf_s("enter the dimensions of b: "); 
    scanf_s("%d", &b); 
    /* Get the user to enter the dimensions of c*/ 
    printf_s("enter the dimensions of c: "); 
    scanf_s("%d", &c);       

    /* Conditions of a triangle*/ 
    if ("a + b > c && a + c > b && b + c > a") 

     printf_s("True\n");  /* Display True if able to make a triangle*/ 

    else printf_s("False\n"); /* Display false if unable to make a triangle*/ 

    double p = a + b + c; 

    /*Scan user input data a, b, c*/ 
    scanf_s("%d", &a, "%d", &b, "%d", &c); 

    /*output total perimeter*/ 
    printf_s("The perimeter of the triangle is: ""%d, p"); 





    return 0; 
} 

Answer 1

的問題是，所有%d應%lf爲了匹配類型double所取代。

而且還刪除行scanf_s("%d", &a, "%d", &b, "%d", &c);，一旦你掃描一次，就不能再次掃描，以獲得相同的值。