### hamobos499's blog

By hamobos499, 5 weeks ago, ,

## Problem statement

Two friends Kunal and Satyam are playing an interesting game. They take turns drawing a ball from a bag which initially contains R red balls and G green balls. Each player draws a ball alternatively and never put it back. The person who is the first to draw a red balls wins. Satyam always draws first. If there are no more balls in the bag and nobody has drawn a red ball, the satyam wins.

Input -----

The first line will contain the number of test cases T. The first line of each test case will contain a number R (number of red balls) and G(number of green balls )

Cases:

2 1 --> 0.6666667 1 1 ---> 0.50000 10 0 ----> 1.0000

I tired to solve the problem using top-bottom approach but my codes gives wrong answer at the last case (0 instead of 1)

int probability = 0, c = 0;

void magic(int red, int green, int turn){
if(green == -1 || red == -1)return ;
if(red == 0){
probability++;
if(turn % 2 == 0) c++;
return ;
}
if(turn == -1) turn = 0;
else turn++;
magic(red, green-1, turn % 2);
magic(red-1, green, turn % 2);
return ;
}

int main(){

ios::sync_with_stdio(0);
cin.tie(nullptr);

int q;
cin >> q;
while(q--){
int x, y;
cin >> x >> y;
magic(x, y, -1);
cout << fixed << setprecision(9) << c * 1.0 / probability << '\n';
probability = 0, c = 0;
}
return 0;
}


I will appreciate any kind of help from all of you, and thanks for your time

• 0

By hamobos499, history, 6 weeks ago, ,

When I enter my submission page and click in my submission IDs, It doesn't work with me, and so when I enter a problem like and click on my submissions the "Click here to see details" doesn't work too!

• Another problem, I have submittied a problem called CME form yesterday and It got accepted at 31 ms and now I submitted the same exact code and got accepted at 46 ms!

Does someone else have the same Issue as mine?

• +6

By hamobos499, history, 3 months ago, ,

Hi everyone,

This problem gives you two inputs N, M and N contains a number like (123) and all what you have to do is to add some digits on the left or the right of the (123) to make it divisible by M Hint about solving this problem, Or a solution for It?

constrains :- N<= 10^12 and M <= 2 * 10^5

Sample tests:-

(Test 1) 1 2 ===> 10 (Test 2) 2 11 ===> 22 (Test 3)234 823 ===> 12345

• +5

By hamobos499, history, 3 months ago, ,

I has been 6 months since I start to solve problems from any online judge (Codeforces was the first one by the way) but since then, I barely notice a difference in my problem solving skills from now and 6 months ago even I had solve +100 problem and every time I register in a contest (div 2 or 3), my rate always decreases by -90 or more, and even If I managed to solve a problem It would be an A only.

So what should I do to improve my self even more? or begin a professional problem-solver requires lot of years practising? I'll be very grateful If you recommeded a few solutions based on your experience ^^