C++实现两个超大的字符数字相加的算法的代码

Posted 2021-01-26

如下资料是关于C++实现两个超大的字符数字相加的算法的代码。

#include <iostream>
#include <string>
#include <stack>

using namespace std;
void deleteLeadingZeros(string& num){

    if(num[0] == ‘0‘){
        unsigned int strtCpyIndex = 0;
        strtCpyIndex = num.find_first_not_of("0");
        string temp = num.substr(strtCpyIndex);
        num = temp;
    }
}
void equalizeLength(string& num1 , string& num2, char pad = ‘0‘){

    if(num1.size() < num2.size()){
        unsigned int diff = num2.size() - num1.size();
        string temp;
            temp += pad;
        temp += num1;
        num1 = temp;
    }
    else if(num2.size() < num1.size()){
        unsigned int diff = num1.size() - num2.size();
        string temp;
            temp += pad;
        temp += num2;
        num2 = temp;
    }
}

string addLargeNumbers(string num1, string num2)
{   

    if(num1.empty())
        return num2;
    else if(num2.empty())
        return num1;

    stack<short> addResult; 
    string returnResult = "";   

    deleteLeadingZeros(num1);
    deleteLeadingZeros(num2);

    equalizeLength(num1,num2);

    int lastAddElem = num1.size()- 1;

    bool hasCarry = false;

    for(int i = lastAddElem; i >= 0; --i)
    {

        if(result < 10 && !hasCarry)
            addResult.push(result);
        else
        {           
            if(hasCarry){
                hasCarry = result < 10 ? false : true;
                addResult.push(result%10);
            }
            else
            {
                hasCarry = true;
                addResult.push(result % 10 );
            }
        }

    }
    if(hasCarry)
        addResult.push(result/10);

    while(addResult.size()){
        returnResult += (addResult.top() + ‘0‘);        
        addResult.pop();
    }

    return returnResult;
}

int main()
{       
    string num1,num2;
    while(true){
        cout<<"Enter 2 integer for addition : ";
        cin >> num1 >> num2;
        cout <<num1 << "+" << num2 <<" = "<<addLargeNumbers(num1,num2)<<endl;
    }

}