Submission #1027801

#	Time	Username	Problem	Language	Result	Execution time	Memory
1027801		Issa	Tiles (BOI24_tiles)	C++17	19 / 100	41 ms	26652 KiB

Main

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
#define ent "\n"

const int maxn = 1e6 + 100;
const ll INF = (ll)1e18 + 100;
const int inf = 1e9 + 100;
const int MOD = 1e9 + 123;
const int maxl = 26;
const int P = 31;

int n, m;
int a[maxn];
int b[maxn];
int c[1010][1010];

void test(){
	cin >> n >> m;
	bool ok = 1;
	for(int i = 1; i <= n; i++){
		cin >> a[i] >> b[i];
		if(i > 2) ok &= (a[i] >= a[i-1]) & (b[i] >= b[i-1]);
	}
	if(ok && !a[1] && !b[1]){
		vector<int> v;
		for(int i = 2; i <= n; i++){
			while(v.size() > 1){
				int k = v[v.size()-2], j = v.back();
				if(a[k] == a[j] && a[j] == a[i]) v.pop_back();
				else if(b[k] == b[j] && b[j] == b[i]) v.pop_back();
				else break;
			} v.push_back(i);
		}
		int ans = 0;
		for(int i: v){
			if((b[i] & 1 )|| !b[i]) break;
			ans = a[i] - (a[i] & 1);
			if(a[i] & 1) break;
		}
		cout << ans;
	} else{
		for(int i = 1; i <= n; i++){
			int j = i - 1;
			if(!j) j = n;
			if(a[i] == a[j]){
				int l = min(b[i], b[j]);
				int r = b[i] + b[j] - l;
				for(int y = l; y < r; y++){
					c[a[i]][y] ^= 1;
				}
			}
		}
		for(int i = 0; i < m; i++){
			for(int j = 0; j <= 1000; j++){
				if(i) c[i][j] ^= c[i-1][j];
			}
		}
		int ans = 0;
		for(int i = 0; i < m; i++){
			int ok = 0;
			for(int j = 0; j <= 1000; j++){
				if(c[i][j]){
					ok = 1;
					if(c[i+1][j] && c[i][j+1] && c[i+1][j+1]){
						c[i][j] = 0;
						c[i+1][j] = 0;
						c[i][j+1] = 0;
						c[i+1][j+1] = 0;
					} else{
						ok = 2;
						break;
					}
				}
			}
			if(ok == 2) break;
			if(ok == 1) continue;
			ans = i + 1;
		}
		cout << ans;
	}
}

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    int t; t = 1;
    while(t--) test();
    cout << ent;
}

• Subtask 1: 0 / 4
• Subtask 2: 0 / 9
• Subtask 3: 0 / 11
• Subtask 4: 19 / 19
• Subtask 5: 0 / 22
• Subtask 6: 0 / 25
• Subtask 7: 0 / 10