BOOL isValidNumber(char *pNum)
{
char *p = pNum;
short nDecimalCount = 0;
short nSigned = 0;
if(*p == ‘-‘)
{
nSigned = 1;
p++;
}
while((*p) && (*p>=48) && (*p<=57) || (*p==’.’))
{
nDecimalCount++;

if(nDecimalCount>1)
break;
p++;
}
return !(pNum+strlen(pNum)-p);
}

void GetBigAndSmall(char *s1, char *s2, char **pB, char **pS)
{
int l1 = strlen(s1), l2 = strlen(s2);
*pB = l1>=l2? s1: s2;
*pS = l1<l2 ? s1: s2;
}
void __add(char *pB, char *pS, char *pSum)
{
char *pR = pSum;
char *pSe = pS+strlen(pS)-1;
char *pBe = pB+strlen(pB)-1;
int carry =0;
while(*pS)
{
int sum = *pBe+*pSe-96 + carry;
carry = sum/10;
*pR = sum%10+48;
pR++;
pBe–;
pSe–;
pS++;
pB++;
}
while(*pB)
{
int sum = *pBe+carry-48;
carry = sum/10;
*pR = sum%10+48;
pR++;
pBe–;
pB++;
}
*pR = ‘\0’;
}
void Add(char *pNum1, char *pNum2, char *pSum)
{
if(isValidNumber(pNum1)&& isValidNumber(pNum2))
{
char *pS, *pB;
GetBigAndSmall(pNum1, pNum2, &pB, &pS);

__add(pB, pS, pSum);

}
strrev(pSum);
}

int main()
{
char m[256], n[256],Sum[60];//Sum will store the result

cout<<“\nEnter 2 long numbers \n\n”;
cout<<“Enter 1st Num. :>”;