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## Discussion of Problem 1206. Sum of Digits of the Sum of Numbers

non correct statement?
Posted by Mansurov Artur 9 Jul 2008 10:22
for K=2 we can get 1980 only if we assume that pairs
A=12 B=12
A=12 B=12
are two different pairs like
A=11 B=12
A=12 B=11
Re: non correct statement?
Posted by Chmel_Tolstiy 9 Jul 2008 14:44
I think u are not right.
Re: non correct statement?
Posted by bsu.mmf.team 17 Sep 2008 21:46
Yes, see this programm:

#include <iostream>
#include <math.h>

using namespace std;

int Sum (int n)
{
int s=0;
while (n)
{
s+=n%10;
n/=10;
}
return s;
}

int main()
{
int k=0;
for (int i=10; i<100; i++)
{
for (int j=10; j<100; j++)
{
if (Sum(i)+Sum(j)==Sum(i+j))
{
k++; cout<<i<<" "<<j<<"\n";
}
}
}
cout<<k;
return 0;
}

It returns 1980, but you can easily see that if i=j this pair wasn't counted twice