Kortit II

input/code.cpp: In function 'int recurse(int, int, int, std::vector<int>)':
input/code.cpp:24:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   24 |         for (int i = 0; i < used.size(); i++) {
      |                         ~~^~~~~~~~~~~~~
input/code.cpp: In function 'int calculate(int, int, int)':
input/code.cpp:70:23: warning: suggest parentheses around comparison in operand of '^' [-Wparentheses]
   70 |         if (n==0 || (a==0 xor b==0)) {
      |                      ~^~~

#include <bits/stdc++.h>
using namespace std;

#define out_mod 1000000007

int recurse(int n, int a_left, int b_left, vector<int> used) {
	//cout << n << " " << a_left << " " << b_left;
	if (n==1) return 0;
	if (a_left==0 && b_left==0 && n==0) return 1;
	if (b_left==0) return 0;
	if (n==2 && a_left==1 && b_left==1) return 1;
	if (n==2) return 0;
	if (n==3 && a_left==2 && b_left==1) return 1;
	
	//cout << "(";
	int out = 0;
	if (used.size() > 0) {
		int temp = recurse(n-used.size()-1, a_left, b_left - 1, {});
		out += temp;
		//cout << ":" << temp;
	//cout << ";";
	}
	vector<bool> used_numbers(n);
	for (int i = 0; i < used.size(); i++) {
		used_numbers[used[i]] = true;
	}
	if (used.size() > 0){
		for (int i = 1; i < used.back(); i++) {
			if (!used_numbers[i]){
				used.push_back(i);
				int temp = recurse(n, a_left, b_left-1, used);
				out += temp;
				//cout << "-" << i << ":" << temp;
				used.pop_back();
	//cout << ";";
			}
		}
		if (a_left>0) {
			for (int i = used.back() + 1; i < n; i++) {
				if (!used_numbers[i]){
					used.push_back(i);
					int temp = recurse(n, a_left-1, b_left, used);
					out += temp;
					//cout << "-" << i << ":" << temp;
					used.pop_back();
	//cout << ";";
				}
			}
		}
	} else if (a_left>0) {
		for (int i = 1; i < n; i++) {
			if (!used_numbers[i]){
				used.push_back(i);
				int temp = recurse(n, a_left-1, b_left, used);
				out += temp;
				//cout << ":" << temp;
				used.pop_back();
	//cout << ";";
			}
		}
	}
	//cout << ")";
	
	return out;
}

int calculate(int n, int a, int b) {
	int draws = n-a-b;
	//cout << draws;
	if (n==0 || (a==0 xor b==0)) {
		cout << "0\n";
		return 0;
	}
	if (draws < 0) {
		cout << "0\n";
		return 0;
	}
	if (draws == n-1) {
		cout << "0\n";
		return 0;
	}
	
	uint64_t out = recurse(n - draws, max(a,b), min(a,b), {});
	//cout << endl;
	
	int k = draws;
	int s = n-k;
	
	//n!n!/k!s!
	for (int i = min(k,s) + 1; i <= max(k,s); i++) {
		out = (out * i) % out_mod;
	}
	for (int i = max(k,s) + 1; i <= n; i++) {
		out = (out * i * i) % out_mod;
	}
	
	cout << out << "\n";
	
	return 0;
}

int main() {
	int t;
	cin >> t;

	for (int i = 0; i < t; i++) {
		int n,a,b;
		cin >> n >> a >> b;
		calculate(n,a,b);
	}
	return 0;
}

Test 1

Group: 1, 2, 3, 4, 5

Verdict: ACCEPTED

Test 2

Group: 2, 3, 4, 5

Verdict: ACCEPTED

Test 3

Group: 3, 4, 5

Verdict: TIME LIMIT EXCEEDED

Test 4

Group: 4, 5

Verdict: TIME LIMIT EXCEEDED

Test 5

Group: 5

Verdict: TIME LIMIT EXCEEDED

Test 6

Group: 5

Verdict: TIME LIMIT EXCEEDED