Question

In the base conversion problem, the task to be performed is to convert the number of base n to decimal. The base of number can be anything such that all digits are represented using 0 to 9 and A to Z. Value of A is 10, Value for B is 11 and so on. So, write a program to convert a number to decimal Example: Input number is given as string and the output is an integer. Input Output Input Output str "1100", base-"2" 12 str "11A", base-"16" 282 Thus, this is how we convert from a different base to base 10. In general, we can write our conversion as follows: dn-idn-...dzdido (in base b) -dn-1Xbn Hint: "str" is the input number, "base" is base of input number. Decimal equivalent is: str [len-1] x base(len-1) + str [len-2] x base(len-2)+ Note that you will need to convert or cast the char to integer before performing the arithmetic operation Example calculation: 3145-3 x 52+1 x 51 +4 x 50 8410.

Answer 1

#include <iostream>
#include <string>
using namespace std;

int main()
{
char str[10] ;
char base[1];
int b;
int p = 1;
int dec = 0;
int i;
// accept value and base
cout<<"\nEnter Number :: ";
cin>>str;
cout<<"\nEnter base :: ";
cin>>base;
// checkbase to make A as 10 B as 11
if(isdigit(base[0])==true)
b=atoi(base);
else
b=int(base[0])-65+10;
  
int len;
for(len=0;str[len]!='\0';len++);

int s;
// conversion
  
for (i = len - 1; i >= 0; i--)
{
if(isdigit(str[i])==true)
s=int(str[i])-'0';
else
s=int(str[i])-65+10;
  
dec += s * p;
p = p * b;
}
  
cout<<"\nDecimal of number "<<str<<" is :: "<<dec;
return 0;
}

Output

Enter Number:: 11A Enter base:: 16 Decimal of number 11A is :: 282