my solution link :CodeChef: Practical coding for everyone

please help

When you are finding lcm that time you are **multiplying (a*b) which is resulting in integer overflow** .You should **use long long int** instead of int to avoid the overflow.

See here i have changed int to long long int in your solution

Use long long int instead of int even for a and b. This is because (a*b) is stored in int data type and then divided by GCD which causes the integer overflow! in order to understand by yourself, please the test case

5

120 140

10213 312

10 30

1000000 1000000

1000000 999999

The output should be :

20 840

1 3186456

10 30

1000000 1000000

1 999999000000

You just have to change int to long long int in the gcd function as well!! Hope that was a help.

If I might intervene, there’s a quicker/shorter way to do this.

One C++ STL function many are unaware of, is the GCD one : __gcd(a,b)

Now, LCM will be a * b/ __gcd(a,b) and make sure a and b are long long ints. Hope it helps.

Yours

Tom Marvolo Riddle