我如何让这个 C++ 程序使用负数？

Question

#include <iostream>

#include <vector>

using namespace std;

int main()
{    

int value1; // these holds the original numbers inputted by the users
int value2;
int result; 
// this holds the answer to be compared against the answer provided by using the algorithm

cout << "Please Enter the first number to be multiplied"<< endl;
cin >> value1;
cout << "Please Enter the second number to be multiplied"<< endl;
cin >> value2;
int tempnumber1 {value1};   //create a temp variable for halving while  keeping main numbers stored for later use.
vector <int> halving;       // this opens this vector halving which the algorithm uses
cout << "This is the Halving Step" << endl;
do
{
    halving.push_back(tempnumber1);
    cout <<tempnumber1 << endl;
    tempnumber1/=2;
}
while (tempnumber1>0);
cout << " This is the Doubling stage" <<endl;
int tempnumber2 {value2};
for (int i=0;   i<halving.size(); i++)
{
    cout << tempnumber2 << endl;
    tempnumber2*=2;

}


int total{0};
int doubling = value2;
for (int i =0; i < halving.size(); i++)
{


if (halving [i] %2==1)
{
cout << doubling << " Is Added to total" << endl;
total += doubling;

}
doubling *= 2;      // this is used to avoid having to use two vectors.




}
//total /= 2;
result = value1*value2; // this provides the check value
cout << "The result is:" << total;
cout << "[Check Value:" << result << "]" << endl;
}

嗨，这是几个月前我通过的大学作业。 任务是使用 C++ 中的俄罗斯农民乘法工作 但回头看，我意识到它不适用于负数，我该如何让这个程序处理负数？

Answer 1

#include <iostream>
#include <bits/stdc++.h>

using namespace std;

int main()
{

    int value1; // these holds the original numbers inputted by the users
    int value2;
    int result;
    // this holds the answer to be compared against the answer provided by using the algorithm

    cout << "Please Enter the first number to be multiplied"<< endl;
    cin >> value1;
    cout << "Please Enter the second number to be multiplied"<< endl;
    cin >> value2;
    int tempnumber1 {value1};   //create a temp variable for halving while  keeping main numbers stored for later use.
    vector <int> halving;       // this opens this vector halving which the algorithm uses
    cout << "This is the Halving Step" << endl;
    do
    {
        halving.push_back(tempnumber1);
        cout <<tempnumber1 << endl;
        tempnumber1/=2;
    }
    while ((tempnumber1>0 && value1>0) ||(tempnumber1<0 && value1<0));
    cout << " This is the Doubling stage" <<endl;
    int tempnumber2 {value2};
    for (int i=0;   i<halving.size(); i++)
    {
        cout << tempnumber2 << endl;
        tempnumber2*=2;

    }


    int total{0};
    int doubling = value2;
    for (int i =0; i < halving.size(); i++)
    {
        if (abs(halving [i]) % 2==1)
        {
            cout << doubling << " Is Added to total" << endl;
            total += doubling;

        }
        doubling *= 2;      // this is used to avoid having to use two vectors.
    }
    //total /= 2;
    result = value1*value2; // this provides the check value
    cout << "The result is:" << total;
    cout << "[Check Value:" << result << "]" << endl;
}

Answer 2

我能想到的最优雅的：

cout << "This is the Halving Step" << endl;
  do {
    halving.push_back(tempnumber1);
    cout << tempnumber1 << endl;
    tempnumber1 /= 2;
  } while (tempnumber1 != 0);

  int total{0};
  int doubling = value2;
  int sign{0};
  for (int i = 0; i < halving.size(); i++) {
    if ((sign = halving[i] % 2) != 0) {
      cout << doubling*sign << " Is Added to total" << endl;
      total += doubling*sign;
    }
    doubling *= 2;  // this is used to avoid having to use two vectors.
  }

Answer 3

这个；

while (tempnumber1>0);

应该改成这个；

while (tempnumber1>0 || tempnumber1 < 0);
//Or
while (tempnumber1 != 0); //Thanks @besc

还有这个；

if (halving [i] %2==1)

应该改成这个；

if (halving [i] %2==1 || halving [i] %2==-1)
//Or
if(halving[i] % 2 != 0); //Thanks @stefaanv

容纳负数

Answer 4

我认为你可以使用这个（如果我错了，请纠正我）；

while (isdigit(tempnumber1)==0);