并联电路

Question

我在编程时遇到了麻烦。我需要计算并联和串联电路的总电阻值。我有串联电路功能，但我的问题是，当我尝试计算并联电路的总电阻时，我的返回值是1.＃INF。有关如何解决此问题的任何建议

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

    #include "stdafx.h"
    #include <iostream>
    #include <math.h>

    using namespace std;

    void menu()
    {
       cout <<"\t\t\tLab 2 Menu Driven Algorithms" << endl;
       cout <<"\t\t  Calculating Parallel and Series Resistance" << endl;
       cout <<"1)\tSeries" << endl;
       cout <<"2)\tParallel" << endl;
       cout <<"3)\tQuit" << endl;   
    }

    int series(int& num, int& sum)
    {
int answer;
num = 0;
sum = 0;

do
{
    cout << "Enter Resistor " << num+1 << " value, 0 to calculate: ";
    cin >> answer;
    cout << endl;

    sum = sum + answer;

    num++;
}
while(answer != 0);     

return sum;
    }

    double parallel (int& num, double& sum)
    {
double answer;
num = 0;
sum = 0.0;
int counter = 0;

do
{
    cout << "Enter Resistor " << num+1 << " value, 0 to calculate: ";
    cin >> answer;
    cout << endl;
    counter++;

    sum = (1/answer) + sum;
    cout << sum << endl;

    num++;
}
while(answer != 0);

return sum;
    }




    int main()
    {
char choice;
int num = 0;
int sum = 0;
double sum2 = 0.0;

menu();

cout <<"\n\nPlease enter a value from the menu: ";
cin >> choice;
cout << endl;

while (choice != '3' && choice != 'q' && choice != 'Q')
{


switch(choice)
{
    case '1': cout << "Calculating Series Resistance" << endl;
              cout << "The series resistance for the " << num-1 << " resistors is: " << series(num, sum) << " Ohms\n";
              system("pause");
              break;
    case '2': cout << "Calculating Parallel Resistance" << endl;
              cout << "The parallel resistance for the " << num-1 << " resistors is: " << parallel(num, sum2) << " Ohms\n";
              system("pause");
              break;
    default: break;

}

system("cls");

menu();

cout <<"\n\nPlease enter a value from the menu: ";
cin >> choice;
cout << endl;


} 
system("pause");

return 0;
    }

Answer 1

您可能希望以这种方式重写parallel()函数内的循环，这样您就永远不会处理0的值（在这种情况下会导致除以零）：

cout << "Enter Resistor " << num+1 << " value, 0 to calculate: ";
cin >> answer;
cout << endl;

while (answer != 0);     
{
    counter++; // NOTICE: This is never used for computation...

    sum = (1/answer) + sum;
    cout << sum << endl;

    num++;

    cout << "Enter Resistor " << num+1 << " value, 0 to calculate: ";
    cin >> answer;
    cout << endl;
}

counter变量从不用于计算，所以我想你可以摆脱它。

另请注意，即使series()内的循环也有类似的问题，尽管你永远不会导致除以零这一事实并不能使其可见。