Submission #524782

#	Time	Username	Problem	Language	Result	Execution time	Memory
524782		maks007	Table Tennis (info1cup20_tabletennis)	C++14	87 / 100	733 ms	4200 KiB

tabletennis

#include <bits/stdc++.h>
 
using namespace std;
 #define break_it assert(false)
int main(void) {
	ios::sync_with_stdio(0);
	cin.tie(0);
	int n, k;
	cin >> n >> k;
	vector <int> a(n+k);
	for(int i = 0; i < n +k; i ++) cin >> a[i];
	function <void(int)> check=[&](int sum) {
		vector <int> ans;
		int l = 0, r = n + k - 1;
		while(l < r) {
			if(a[l] + a[r] == sum) {
				
				ans.push_back(a[l]);
				ans.push_back(a[r]);
				l ++;
				r --;
			}else if(a[l] + a[r] > sum) {
				r--;
			}else l ++;
			if(ans.size() == n) break;
		}
		if(ans.size() == n) {
			sort(ans.begin(), ans.end());
			for(auto i : ans) cout << i << " ";
			exit(0);
		}
	};

	function <int(vector <int>)> checkv=[](vector <int> s) {
		int n = s.size();
		for(int i = 0; i < n; i ++) {
			int j = i + 1;
			if(j >= n or n - i - 1 < 0 or n - j - 1 < 0) break;
			if(s[i] + s[n-i-1] == s[j]+s[n-j-1]) continue;
			return 0;
		}
		return 1;
	};
		function <void(int, int, int)> solve=[&](int start, int end, int sm = 0) {
		vector <int> fors;
		int sum = 0;
		if(start == end and end == -1) sum = sm;
		else sum = a[start] + a[end];
		int none = -1;
		int l = 0, r = n+k-1;
		while(l < r){
			if(a[l] + a[r] > sum) {
				if(none != -1) return;
				none = r;
				r--;
			}else if(a[l] + a[r] < sum) {
				if(none != -1) return;
				none = l;
				l ++;
			}
			l ++;
			r --;
		}
		if(none == -1) {
			none = (n+k)/2;
		}
		for(int i = 0; i <= n+k-1; i ++) {
			if(none == i) continue;
			fors.push_back(a[i]);
		}
		for(auto i : fors) cout << i << " ";
		exit(0);
	};	
	if(n+k<=18) {
		for(int mask = 0; mask < (1 << (n+k)); mask ++) {	
			if(__builtin_popcount(mask) == n) {
				vector <int> v;
				for(int i = 0; i < n+k; i ++) {
					if((mask & (1 << i))!=0) {
						v.push_back(a[i]);
					}
				}
				if(checkv(v)) {
					for(int i = 0; i < v.size(); i ++) cout << v[i] << " ";
					return false;
				}
			}
		}
		return false;
	}else if(k == 1) {
		solve(0, n+k-1, 0);
		solve(0, n+k-2, 0);
		solve(1, n+k-1, 0);
	}else if((k <= 20 and n <= 150000)or(n<=100 and k <=100)){
		
		set <int> sums;
		for(int i = 0; i < k+1; i ++) {
			for(int j = n-k-1; j < n +k; j ++) {
				sums.insert(a[i] + a[j]); 
			}
		}
		for(auto i : sums) {
			check(i);
			
		}
	}else {
		set <int> sums;
		for(int i = k; i < 2*k; i ++) {
			for(int j = n-k; j < n; j ++) {
				sums.insert(a[i] + a[j]);
			}
		}
		for(auto i : sums) {
			check(i);
		}
	}
		
	return false;
}  

Compilation message (stderr)

tabletennis.cpp: In lambda function:
tabletennis.cpp:25:18: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   25 |    if(ans.size() == n) break;
      |       ~~~~~~~~~~~^~~~
tabletennis.cpp:27:17: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   27 |   if(ans.size() == n) {
      |      ~~~~~~~~~~~^~~~
tabletennis.cpp: In function 'int main()':
tabletennis.cpp:84:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   84 |      for(int i = 0; i < v.size(); i ++) cout << v[i] << " ";
      |                     ~~^~~~~~~~~~

• Subtask 1: 11 / 11
• Subtask 2: 9 / 9
• Subtask 3: 14 / 14
• Subtask 4: 15 / 15
• Subtask 5: 9 / 9
• Subtask 6: 14 / 14
• Subtask 7: 15 / 15
• Subtask 8: 0 / 13