Question

How to calculate the sum of digits of 2 power 100 in C++

Answer 1

#include <iostream>
#include <cmath>

int sumDigits(char array[]) {
    int sum = 0;
     
    for(int i = 0; array[i]; i++) {
        if (array[i] != '.') {
            sum += (array[i] - '0');
        }
    }  
      
    return sum;
}
 
int main()
{
    int base = 2;
    int exponent = 100;
    
    double power = pow(base, exponent); 
      
    printf("%lf\n", power);
 
    char array[64] = "";
 
    snprintf(array, 32, "%.32f", power);
 
    std::cout << "sum = " << sumDigits(array);
}
   
    
    
    
/*
run:
 
1267650600228229401496703205376.000000
sum = 115
 
*/

 

70+ SQL courses for beginners and professionals