I calculated the total possible solutions which will be nC3 and then subtracted the number of bad combinations(observe that in a bad combination 2 problems will be having the same topic type and 2 problems will be having the same difficulty).

How to solve E?

Thanks man, turns out I was not setting the columns in result grid and was trying to access columns without setting them, it was a stupid mistake :(

I tried doing problem C(Palindromic Crossword) using some dfs kind algorithm(I stored nearest blockages for each row and column) and kept getting runtime error, can someone point out the mistake in my logic? Thanks link: https://pastebin.com/Xx3KHbGU

Google giving Codechef vibes :(

How to solve E?

What's the idea behind E2? Can it be solved using Z function?

How to solve C?

How to solve beautiful permutations?

How to solve D?

How to do total overlap?

How to solve problem D using top-down approach?

How to solve C?

How to solve D(div2)?

In C,for solving for x-axis, why is it wrong to just sort the x coordinates and start mapping them to x[n/2]-n/2, x[n/2]-n/2+1, x[n/2]-n/2+2 and so on... here is my logic, i can't figure out what's wrong

void solve () {
	ll n;
	cin >> n;
	vector<ll> x(n),y(n);
	for (int i = 0;i < n;++i) {
		cin >> x[i] >> y[i];
	}
	sort(all(x));
	sort(all(y));
	ll finalY = y[n/2];
	ll startX = x[n/2]-n/2;
	ll ans = 0;
	for (int i = 0;i < n;++i) {
		ans += abs(x[i]-startX)+abs(y[i]-finalY);
		++startX;
	}
	cout << ans << '\n';

}

How to solve div2-B(valuable paper)? Thanks in advance:)

I also thought of the same approach but couldn't figure out which n/2 elements to eliminate from the sum.Could you help a little more on how to do the dp part?

How to solve D? Thanks in advnce:)

How to solve E and F? Thanks in advance:)