Question

In C++

Do not use classes. Write a function to add two integers of any length, say up to 200 digits. he suggested approach as follows: treat each number as a list array, each of those elements is a block of digits of that number ( say block of 1 to 4 digits, your choice). For example the integer 123456789101112 might be stored as N(1)=1112, N(2)=8910, N(3)=4567, N(4)=123. then add two integers (list) element by element, caring from one element to the next one necessary. Then write a function to multiply two large energizers of any length, say to a hundred digits. cuz your functions in the main program that reads to large integers, calls the function, and finds their sum and product.

Answer 1

CODE:

#include<bits/stdc++.h>

using namespace std;

string add(string str1, string str2)

{

if (str1.length() > str2.length())

swap(str1, str2);

string str = "";

int n1 = str1.length(), n2 = str2.length();

reverse(str1.begin(), str1.end());

reverse(str2.begin(), str2.end());

int carry = 0;

for (int i=0; i<n1; i++)

{

int sum = ((str1[i]-'0')+(str2[i]-'0')+carry);

str.push_back(sum%10 + '0');

carry = sum/10;

}

for (int i=n1; i<n2; i++)

{

int sum = ((str2[i]-'0')+carry);

str.push_back(sum%10 + '0');

carry = sum/10;

}

if (carry)

str.push_back(carry+'0');

reverse(str.begin(), str.end());

return str;

}

string multiply(string num1, string num2)

{

int len1 = num1.size();

int len2 = num2.size();

if (len1 == 0 || len2 == 0)

return "0";

vector<int> result(len1 + len2, 0);

int i_n1 = 0;

int i_n2 = 0;

for (int i=len1-1; i>=0; i--)

{

int carry = 0;

int n1 = num1[i] - '0';

i_n2 = 0;

for (int j=len2-1; j>=0; j--)

{

int n2 = num2[j] - '0';

int sum = n1*n2 + result[i_n1 + i_n2] + carry;

carry = sum/10;

result[i_n1 + i_n2] = sum % 10;

i_n2++;

}

if (carry > 0)

result[i_n1 + i_n2] += carry;

i_n1++;

}

int i = result.size() - 1;

while (i>=0 && result[i] == 0)

i--;

if (i == -1)

return "0";

string s = "";

while (i >= 0)

s += to_string(result[i--]);

return s;

}

int main()

{

string str1 = "121258676969696961231235";

string str2 = "198111456793120125312391526123";

cout << "Sum = " << add(str1, str2) << endl;

cout << "Product = " << multiply(str1, str2);

return 0;

}