Submission #667316

#	Time	Username	Problem	Language	Result	Execution time	Memory
667316		Kalashnikov	Nice sequence (IZhO18_sequence)	C++17	15 / 100	20 ms	956 KiB

sequence

#include <bits/stdc++.h>
 
#define ios ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)
#define file(s) if (fopen(s".in", "r")) freopen(s".in", "r", stdin), freopen(s".out", "w", stdout)
#define all(a) a.begin() , a.end()
#define F first
#define S second
 
using namespace std;
using ll = long long;
 
const int N = 2e5+5 , inf = 2e9 + 7;
const ll INF = 1e18 ,   mod = 1e9+7 , P = 6547;
 
int n, m;
vector<int> ans;
 
bool ch(int len) {
	int pos = m;
	int neg = -m*(n-1)-1;
	for(int p = 0; p < n; p ++) {
		vector<int> vec;
		int s1=0, s2 = 0 , ok = 1;
		for(int i = 1; i <= len; i ++) {
			if(i%n == p) {
				vec.push_back(neg);
			}
			else {
				vec.push_back(pos);
			}
			s1 += vec.back();
			s2 += vec.back();
			if(vec.size() > n) {
				s1 -= vec.end()[-n-1];
			}
			if(vec.size() > m) {
				s2 -= vec.end()[-m-1];
			}
			if(i >= n && s1 >= 0) {
				ok = 0;
				break;
			}
			if(i >= m && s2 <= 0) {
				ok = 0;
				break;
			}
		}
		if(ok) {
			ans = vec;
			return 1;
		}
	}
	
	neg = -m;
	pos = m*(m-1)-1;
	for(int p = 0; p < n; p ++) {
		vector<int> vec;
		int s1=0, s2 = 0 , ok = 1;
		for(int i = 1; i <= len; i ++) {
			if(i%n == p) {
				vec.push_back(pos);
			}
			else {
				vec.push_back(neg);
			}
			s1 += vec.back();
			s2 += vec.back();
			if(vec.size() > n) {
				s1 -= vec.end()[-n];
			}
			if(vec.size() > m) {
				s2 -= vec.end()[-m];
			}
			if(i >= n) {
				if(s1 >= 0 || s2 <= 0) {
					ok = 0;
					break;
				}
			}
		}
		if(ok) {
			ans = vec;
			return 1;
		}
	}
	return 0;
}
 
void solve(int tc) {
	cin >> n >> m;
	int coef = 1;
	if(n > m) {
		swap(n , m);
		coef *= -1;
	}
	if(m % n == 0) {
		cout << m-1 << '\n';
		for(int i = 1; i < m; i ++) {
			cout << (-1)*coef << ' ';
		}	
		cout << '\n';
		// return;c
		return;
	}
	int l = m , r = 2*m;
	while(l <= r) {
		int md = l+r >> 1;
		if(ch(md)) {
			l = md+1;
		}
		else {
			r = md-1;
		}
	}
	cout << ans.size() << '\n';
	for(auto x: ans) {
		cout << x*coef << ' ';
	}
	cout << '\n';
}
/*
*/
main() {
    ios;
    int tt = 1 , tc = 0;
    cin >> tt;
    while(tt --) {
        solve(++tc);
    }
    return 0;
}

Compilation message (stderr)

sequence.cpp: In function 'bool ch(int)':
sequence.cpp:33:18: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   33 |    if(vec.size() > n) {
      |       ~~~~~~~~~~~^~~
sequence.cpp:36:18: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   36 |    if(vec.size() > m) {
      |       ~~~~~~~~~~~^~~
sequence.cpp:68:18: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   68 |    if(vec.size() > n) {
      |       ~~~~~~~~~~~^~~
sequence.cpp:71:18: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   71 |    if(vec.size() > m) {
      |       ~~~~~~~~~~~^~~
sequence.cpp: In function 'void solve(int)':
sequence.cpp:107:13: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  107 |   int md = l+r >> 1;
      |            ~^~
sequence.cpp: At global scope:
sequence.cpp:123:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
  123 | main() {
      | ^~~~

• Subtask 1: 6 / 6
• Subtask 2: 9 / 9
• Subtask 3: 0 / 14
• Subtask 4: 0 / 15
• Subtask 5: 0 / 14
• Subtask 6: 0 / 18
• Subtask 7: 0 / 24