c++ - 添加 2 个二进制数作为字符串，C++

Question

我在添加 2 个二进制数时遇到问题。我想以字符串的形式执行此操作，因此如果它们的长度不同，我将“0”连接到较短字符串的开头。首先，我不知道为什么，但我需要衬底然后添加“0”(没有它，它根本不起作用)。

#include <iostream>
using namespace std;


string add( string no1, string no2 );


int equalizer(string no1, string no2)
{
int len1 = no1.length();
int len2 = no2.length();
if (len1 < len2)
{
    for (int i = 0 ; i < len2 - len1 ; i++)
    {

        no1 = '0' + no1;
    }
    return len2;
 }
 else if (len1 >= len2)
 {
    for (int i = 0 ; i < len1 - len2 ; i++)
    {

        no2 = '0' + no2;
    }
    return len1; // If len1 >= len2
 }

 }


 string add( string no1, string no2 )
 {
  string result="";


  int length = equalizer(no1, no2);

 int carry = 0;


 for (int i = length-1 ; i >= 0 ; i--)
 {
    int bit1 = no1.at(i) - '0';
    int bit2 = no2.at(i) - '0';

    // boolean expression for sum of 3 bits
    int sum = (bit1 ^ bit2 ^ carry)+'0';

    result = (char)sum + result;

    // boolean expression for 3-bit addition
    carry = (bit1 & bit2) | (bit2 & carry) | (bit1 & carry);
  } 

  // if overflow, then add a leading 1
  if (carry)
 {


    result = '1' + result;
  }

  return result;
  }
 bool check(string no1)
 {
 for(int i =0; i<no1.length(); i++)
 {
    if(no1.at(i)!=0 || no1.at(i)!=1)
    {
        cout << "not biniary! should contain only '0' and '1' "<< endl;
        return false;
    }
    else
    {
        return true;
    }
   }
  }
 int main()
 {
 string no1;
 string no2;
 cout << "Welcome to program that add 2 biniary numbers!" << endl;
 cout <<"Give first number " <<endl;
 cin >> no1;
 if(check(no1)==true)
 {





    cout <<"Give 2nd number" << endl;
    cin >> no2;
    check(no2);
    cout << "Numbers are proper!" << endl;
    add(no1,no2);
 }
 else
 {
    cout <<"End of program."<<endl;
 }
 return 0;
 }

Answer 1

我不添加尾随零，而是在开头反转字符串:std::reverse(s1.begin(), s1.end())。然后我会从开始添加每个数字。 res[i] = s1[i] - s2[i] + '0'; 记得初始化 res 字符串，然后再反转回来!祝你好运!