Відповідь:

C++ code:

#include <iostream>

#include <cstdlib>

#include <ctime>

class Number{

private:

int size;

int *numbers;

public:

Number();

Number(const Number&);

~Number();

void print();

int index_max_sum_digit();

int sum_digit(int);

};

Number::Number(){    

srand(time(NULL));

this->size = 25;

numbers = new int[this->size];

for(int i = 0; i < this->size; i++){

 numbers[i] = rand() % 899 + 100;

}

}

Number::Number(const Number& object){

this->size = object.size;

for(int i = 0; i < this->size; i++){

 numbers[i] = object.numbers[i];

}

}

Number::~Number(){

delete[] numbers;

}

void Number::print(){

for(int i = 0; i < this->size; i++){

 std::cout << numbers[i] << "\t";

}

std::cout << std::endl;

}

int Number::sum_digit(int num){

int sum = 0;

while(num){

 sum += num % 10;

 num /= 10;

}

return sum;

}

int Number::index_max_sum_digit(){

int number,sum = 0,index;

for(int i = 0; i < this->size; i++){

 number = numbers[i];

 int return_sum = sum_digit(number);

 if(return_sum > sum){

  sum = return_sum;

  index = i;

 }

}

return index;

}

int main(){

Number obj;    

obj.print();

std::cout << "index: " << obj.index_max_sum_digit() << std::endl;

return 0;

}