只是学习C++，我很喜欢编写我的第一个程序，它只是解决了数学问题，据我所知，我的逻辑是正确的sqrt((x2-x1)+(y2-y1))，但是距离公式存在一些问题。但是我得到了错误
奖励问题...是否有人可以指出我一种在完成先前的选择之后将用户引导回第一个菜单的方法。我假设存在某种循环，但是我的C++类中尚未涵盖该循环。
这是代码(很抱歉，如果它很乱，但是我还没学会正确的格式)
#include "stdafx.h"
#include <iostream>
#include <cstdlib>
#include <cmath>
using namespace std;
int selection;
int choice;
int choice2;
double height;
double length;
double a;
double x;
double y;
double const pi = 3.14;
double r;
double m;
double x1;
double x2;
double y1;
double y2;
double distance;
int main(){
cout<<"-------------------------"<<endl;
cout<<" MATH DESTROYER "<<endl;
cout<<"-------------------------"<<endl;
cout<<" 1-Geometry Solver "<<endl;
cout<<" 2-Algebra Solver "<<endl;
cout<<" 3-"<<endl;
cout<<endl;
cout<<" Select Option number: "<<endl;
cin>>selection;
cout<<endl;
cout<<endl;
switch(selection){
case 1:
cout<<"-------------------------"<<endl;
cout<<" GEOMETRY SOLVER ";cout<<endl;
cout<<endl;
cout<<" 1-Perimeter of a square "<<endl;
cout<<" 2-Area of a square "<<endl;
cout<<" 3-Perimeter of a rectangle"<<endl;
cout<<" 4-Area of a rectangle "<<endl;
cout<<" 5-Perimeter of a circle "<<endl;
cout<<" 6-Area of a circle "<<endl;
cout<<" Select Option number: "<<endl;
cout<<"-------------------------"<<endl;
cin>>choice;
cout<<endl;
cout<<endl;
switch(choice){
case 1:
cout<<"-------------------------"<<endl;
cout<<" PERIMITER OF A SQUARE "<<endl;
cout<<endl;
cout<<"Enter Height"<<endl;
cin>>height;
cout<<"Enter Length"<<endl;
cin>>length;
cout<<"Perimiter of Square ="<<(height*2)+(length*2)<<endl;
cout<<"-------------------------"<<endl;
cout<<endl;
cout<<endl;
system("pause");
return 0;
case 2:
cout<<"AREA OF A SQUARE"<<endl;
cout<<endl;
cout<<"Enter Length"<<endl;
cin>>length;
cout<<endl;
cout<<endl;
cout<<"FORMULA L^2";
cout<<endl;
cout<<endl;
cout<<"AREA of Square ="<<pow(length,2)<<endl;//(pow)(length,2)= length to the power of 2 or lenght^2
cout<<endl;
cout<<endl;
system("pause");
return 0;
case 3:
cout<<"PERIMITER OF A RECTANGLE"<<endl;
cout<<endl;
cout<<"Enter Height"<<endl;
cin>>height;
cout<<"Enter Length"<<endl;
cin>>length;
cout<<endl;
cout<<endl;
cout<"FORMULA L2+H2";
cout<<endl;
cout<<endl;
cout<<"Perimiter of Rectangle ="<<(height*2)+(length*2)<<endl;
cout<<endl;
cout<<endl;
system("pause");
return 0;
case 4:
cout<<"AREA OF A RECTANGLE"<<endl;
cout<<endl;
cout<<"Enter Height"<<endl;
cin>>height;
cout<<"Enter Length"<<endl;
cin>>length;
cout<<endl;
cout<<endl;
cout<"FORMULA L2+H2";
cout<<endl;
cout<<endl;
cout<<"Perimiter of Rectangle =" <<height*length<<endl;
cout<<endl;
cout<<endl;
system("pause");
return 0;
case 5:
cout<<"PERIMITER OF A CIRCLE"<<endl;
cout<<endl;
cout<<"Enter Radius"<<endl;
cin>>r;
cout<<endl;
cout<<endl;
cout<<"FORMULA peremiter=PI X D";
cout<<endl;
cout<<endl;
cout<<"Perimiter of circle ="<<pi*(r*2)<<endl;
cout<<endl;
cout<<endl;
system("pause");
return 0;
case 6:
cout<<"AREA OF A CIRCLE"<<endl;
cout<<endl;
cout<<"Enter Radius"<<endl;
cin>>r;
cout<<endl;
cout<<endl;
cout<<"FORMULA PI X R^2";
cout<<endl;
cout<<endl;
cout<<"Area of Circle ="<<pi*(pow(r,2))<<endl;
cout<<endl;
cout<<endl;
system("pause");
return 0;
}
case 2:
cout<<" ALGEBRA MASTER "
cout<<"-------------------------"<<endl;
cout<<" 1-Distance Formula "<<endl;
cout<<" 2-Slope "<<endl;
cout<<" 3-Pythagorean Theorm "<<endl;
cout<<"-------------------------"<<endl;
cout<<endl;
cout<<"Select Option number:"<<endl;
cin>>choice2;
switch(choice2){
case 1:
cout<<"Distance Formula"<<endl;
cout<<endl;
cout<<"Enter first y point (y1)"<<endl;
cin>>y1;
cout<<endl;
cout<<"Enter second y point (y2)"<<endl;
cin>>y2;
cout<<endl;
cout<<"Enter first x point (x1)"<<endl;
cin>>x1;
cout<<endl;
cout<<"Enter second x point (x2)"<<endl;
cin>>x2;
cout<<"D=sqrt (x2-x1)+(y2-y1)";
cout<<endl;
cout<<endl;
cout<<"Distance ="<<sqrt((x2-x1)+(y2-y1))<<endl;
cout<<endl;
cout<<endl;
system("pause");
return 0;
case 2:
cout<<"AREA OF A CIRCLE"<<endl;
cout<<endl;
cout<<"Enter Radius"<<endl;
cin>>r;
cout<<endl;
cout<<endl;
cout<<"FORMULA PI X R^2";
cout<<endl;
cout<<endl;
cout<<"Area of Circle ="<<pi*(pow(r,2))<<endl;
cout<<endl;
cout<<endl;
system("pause");
return 0;
case 3:
cout<<"AREA OF A CIRCLE"<<endl;
cout<<endl;
cout<<"Enter Radius"<<endl;
cin>>r;
cout<<endl;
cout<<endl;
cout<<"FORMULA PI X R^2";
cout<<endl;
cout<<endl;
cout<<"Area of Circle ="<<pi*(pow(r,2))<<endl;
cout<<endl;
cout<<endl;
system("pause");
return 0;
}
}
}
最佳答案
我认为主要问题是您的全局变量y1可能与math.h(或cmath)中定义的函数冲突。您可以通过在main()函数中局部声明变量(而不是全局变量)来解决此问题。这样就可以使变量名掩盖现有功能，并避免冲突。
编辑:替代解决方案是将y1重命名为其他名称，例如Y1(大写)。
代码中还有其他两个问题。在两个地方，您得到了cout<而不是cout <<，并且您还缺少了分号。
关于c++ - 编译错误: “pointer can only be subtracted from another pointer”，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/19824557/