english number to decimal number code example

Example 1: english to decimal

#include<iostream>
#include<string>
#include<limits>

inline std::string binary_conv(int,int,std::string);

int main()
{
    long int number;
    int base {27};
    std::cout<<"\nPlease enter a non-negative integer:\t";
    std::cin>>number;


    while(1)
    {
        if(std::cin.fail())
        {
        std::cin.clear();
        std::cin.ignore(std::numeric_limits<std::streamsize>::max(),'\n');
        std::cout<<"\nYou have entered wrong input!"<<std::endl;
        std::cout<<"\nPlease enter a non-negative integer:\t";
        std::cin>>number;
    }
        if(!std::cin.fail())
        break;
    }
    
    std::string binary_number;
    binary_number = binary_conv(number,base,binary_number);
    
    
    std::cout<<binary_number<<std::endl;
   
    return 0 ;
}

std::string binary_conv(int number, int base,std::string binary)
{   
    std::string zero_one = " abcdefghijklmnopqrstuvwxyz";
    if(number==0)
        return binary;
    binary = zero_one[number%base]+binary;
    number/=base;
    return binary_conv(number,base,binary);
}

Example 2: english to decimal

#include<iostream>
#include<cmath> 
#include<limits>
#include<string>
void print_value(const size_t value);
// bool IllegalCharacters(int,const std::string, int);
bool isalpha_isspace(const std::string&);


int main()
{
    std::string eng2dec;
    std::cout<<"\nPlease enter a string of small letters and spaces:\t";
    getline(std::cin,eng2dec);

    // checking if string is an alphabet or spaces 
    bool answer = isalpha_isspace(eng2dec);
    if(answer == false)
    {
        std::cout<<"\nThe input string does not represent a number in base 27"<<std::endl;
        exit(1);
    }
    // looping throught the string and converting the value of chars to decimal with base 27
    size_t value {0};
    int decimal {0};
    for(size_t i {0}; i<eng2dec.length(); ++i)
    {   
        if(eng2dec[i]==' ')
        {
            decimal=0;
        }else{
            int power = (eng2dec.length()-1-i);
            decimal = eng2dec[i]%96;   
            value+= decimal*pow(27,power); 
        }
        if(value > pow(2,32)){
            std::cout<<"\nThe input string represents a number that is greater than 2ˆ32" <<std::endl;exit(1);
        } 
    }
    print_value(value);  
    return 0 ;
}

// check if string is not alphabet or space 
bool isalpha_isspace(const std::string& str )
{   
    bool answer ;
    for(char c: str){
        if(isalpha(c) || isspace(c)) 
        {
           answer = true;
        }else
        {
           answer= false;
        }
    }
    return answer ;
}

// print value 
void print_value(const size_t value){
	std::cout<<value<<std::endl;         
}