#include <iostream>
using namespace std;
#define ARRAY_SIZE 50
//Enter a big number, and store it as a string into an array ch,
//the size is the numbers of char.
void inputNumbers(char ch[], int& size);
//Reverse the elements of the array ch.
void reverseArray(char ch[], int size);
//Adding two big numbers, and the result will be stored in the array ch3,
//and return the size of the array ch3.
void computeAdding(char ch1[], int size1, char ch2[], int size2, char ch3[], int& size3);
//show the adding result.
void displayResult(char ch[], int size);
int main()
{
char ch1[ARRAY_SIZE], ch2[ARRAY_SIZE], result[ARRAY_SIZE];
int size1 = 0, size2 = 0, resultSize = 0;
cout << "Enter the first big number, ending with an enter:" << endl;
inputNumbers(ch1, size1);
cout << "Enter the second big number, ending with an enter:" << endl;
inputNumbers(ch2, size2);
reverseArray(ch1, size1);
reverseArray(ch2, size2);
computeAdding(ch1, size1, ch2, size2, result, resultSize);
displayResult(result, resultSize);
system("pause");
return 0;
}
//Function inputNumbers
void inputNumbers(char ch[], int& size)
{
char next;
cin.get(next);
while (next != '\n' && size < ARRAY_SIZE)
{
ch[size++] = next;
cin.get(next);
}
}//inputNumbers
//Function reverseArray
void reverseArray(char ch[], int size)
{
int i = 0, j = size-1;
char temp;
while (i <= j)
{
temp = ch[i];
ch[i] = ch[j];
ch[j] = temp;
i ++;
j --;
}
}//end reverseArray function
//function computeAdding's definition
void computeAdding(char ch1[], int size1, char ch2[], int size2, char ch3[], int& size3)
{
int i,
tmp, //As the temporary sum of two array elements.
carryBit = 0; //The carry-bit is initialized to zero
for (i = 0; i < size1 && i < size2; i++)
{
tmp = (ch1[i]-'0') + (ch2[i]-'0') + carryBit;
ch3[i] = tmp % 10 + '0';
carryBit = tmp/10;
}
while ( i<size1 ) { //If the array ch1 has more bits, execute this while loop.
tmp = (ch1[i] - '0') + carryBit;
ch3[i] = tmp % 10 + '0';
carryBit = tmp / 10;
i ++;
}
while ( i < size2 ){
tmp = (ch2[i] - '0') + carryBit;
ch3[i] = tmp % 10 +'0';
carryBit = tmp / 10;
i ++;
}
if( carryBit)
{
ch3[i] = carryBit + '0';
i ++;
}
ch3[i] = '\0';
size3 = i;
}//End reverseArray
//function displayResult
void displayResult(char ch[], int size)
{
reverseArray(ch, size);//make the number to be normal
cout << "The adding result is:" ;
for (int i = 0; i < size; i++)
cout << ch[i] ;
cout << endl;
}