Submission #1232920

#	Time	Username	Problem	Language	Result	Execution time	Memory
1232920		lanaskarica	Linear Garden (IOI08_linear_garden)	C++20	100 / 100	36 ms	36580 KiB

linear_garden

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

#define ll long long 
#define pii pair <int, int>
#define fi first
#define se second

const int MAXN = 1e6 + 1;

int MOD, dp[2][3][3][2], sol[MAXN][3][3];

int add(int a, int b) {
	a += b;
	if (a >= MOD) a -= MOD;
	return a;
}

int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	
	string s;
	int n;
	cin >> n >> MOD >> s;
	
	dp[0][1][0][0] = 1;
	dp[0][0][1][1] = 1;
	sol[1][1][0] = 1;
	for (int i = 2; i <= n; i++) {
		for (int j = 1; j <= 2; j++) {
			dp[1][j][0][0] = dp[0][j - 1][0][0];
			dp[1][0][j][1] = dp[0][0][j - 1][1];
			for (int z = 0; z <= 1; z++) {
				dp[1][j][z][0] = add(dp[1][j][z][0], dp[0][j - 1][z + 1][0]);	
				dp[1][j][z][0] = add(dp[1][j][z][0], dp[0][j - 1][z + 1][1]);
				
				dp[1][z][j][1] = add(dp[1][z][j][1], dp[0][z + 1][j - 1][0]);	
				dp[1][z][j][1] = add(dp[1][z][j][1], dp[0][z + 1][j - 1][1]);
			}
		}
		
		for (int j = 0; j <= 2; j++) {
			for (int z = 0; z <= 2; z++) {
				sol[i][j][z] = dp[1][j][z][0];
				for (int r = 0; r < 2; r++) {
					dp[0][j][z][r] = dp[1][j][z][r];
					dp[1][j][z][r] = 0;
				}
			}
		}
	}
	
	int rj = 0, x = 0, y = 0;
	for (int i = 0; i < n; i++) {
		if (s[i] == 'L') {
			x++; y = max(0, y - 1);
			continue;
		}
		for (int j = 0; j <= (2 - x); j++) {
			for (int z = 0; z <= (2 - y); z++) {
				rj = add(rj, sol[n - i][j][z]);
			}
		}
		x = max(0, x - 1); y++;
	}
	cout << add(rj, 1) << "\n";
	
	return 0;
}

• Subtask 1: 2 / 2
• Subtask 2: 2 / 2
• Subtask 3: 4 / 4
• Subtask 4: 4 / 4
• Subtask 5: 4 / 4
• Subtask 6: 4 / 4
• Subtask 7: 4 / 4
• Subtask 8: 4 / 4
• Subtask 9: 4 / 4
• Subtask 10: 4 / 4
• Subtask 11: 4 / 4
• Subtask 12: 5 / 5
• Subtask 13: 5 / 5
• Subtask 14: 5 / 5
• Subtask 15: 5 / 5
• Subtask 16: 5 / 5
• Subtask 17: 5 / 5
• Subtask 18: 5 / 5
• Subtask 19: 5 / 5
• Subtask 20: 5 / 5
• Subtask 21: 5 / 5
• Subtask 22: 5 / 5
• Subtask 23: 5 / 5