From ac539fe4aa93fc68aff6661c616d3489645896d3 Mon Sep 17 00:00:00 2001
From: Anthony Wang <ta180m@gmail.com>
Date: Tue, 6 Oct 2020 17:29:00 -0500
Subject: [PATCH] Add garden.cpp

---
 08/garden.cpp | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)
 create mode 100644 08/garden.cpp

diff --git a/08/garden.cpp b/08/garden.cpp
new file mode 100644
index 0000000..bb68420
--- /dev/null
+++ b/08/garden.cpp
@@ -0,0 +1,31 @@
+#include <bits/stdc++.h>
+#define f first
+#define s second
+using namespace std;
+using ll = long long;
+using ii = pair<int, int>;
+constexpr int MX = 1e6+5;
+
+int p2[MX] = { 1 };
+
+int main() {
+	if (fopen("in", "r")) freopen("in", "r", stdin), freopen("out", "w", stdout);
+	ios_base::sync_with_stdio(0), cin.tie(0);
+
+	int N, M; cin >> N >> M;
+	string S; cin >> S;
+
+	for (int i = 0; i < N; ++i) p2[i+1] = 2*p2[i]%M;
+
+	int ans = 1, cnt = 0, l = 0, h = 0;
+	for (int i = 0; i < N; ++i) {
+		if (S[i] == 'P') {
+			int a = min(cnt-1, l), b = max(cnt-1, h);
+			if (abs(b-a) == 1) (ans += p2[(N-i-1)/2]+p2[(N-i)/2]-1) %= M;
+			else if (abs(b-a) == 2) (ans += p2[(N-i-(cnt != a))/2]) %= M;
+		}
+		cnt += (S[i] == 'P' ? 1 : -1);
+		l = min(cnt, l), h = max(cnt, h);
+	}
+	cout << ans;
+}