P6226 [BalticOI 2019 Day1]潜艇

https://www.luogu.com.cn/record/93519365

Luogu/P6226/P6226.cpp

@@ -0,0 +1,67 @@
+#include <iostream>
+#include <array>
+#include <bitset>
+#include <numeric>
+#include <string>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const int N = 505,
+          M = 5005;
+
+int r, c, m, p;
+std::string s;
+std::array<std::bitset<N>, N> f[M], g;
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    cin >> r >> c >> m;
+
+    for (int i = 1; i <= r; i++) {
+        for (int j = 1; j <= c; j++) {
+            char ch;
+
+            cin >> ch;
+
+            g[i].set(j, ch == '.');
+        }
+    }
+
+    cin >> s;
+
+    f[0] = g;
+
+    for (char op : s) {
+        p++;
+
+        if (op == 'N') {
+            for (int i = 1; i <= r; i++) {
+                f[p][i] = (f[p - 1][i + 1]) & g[i];
+            }
+        } else if (op == 'E') {
+            for (int i = 1; i <= r; i++) {
+                f[p][i] = (f[p - 1][i] << 1) & g[i];
+            }
+        } else if (op == 'S') {
+            for (int i = 1; i <= r; i++) {
+                f[p][i] = (f[p - 1][i - 1]) & g[i];
+            }
+        } else if (op == 'W') {
+            for (int i = 1; i <= r; i++) {
+                f[p][i] = (f[p - 1][i] >> 1) & g[i];
+            }
+        } else {  // op == '?'
+            for (int i = 1; i <= r; i++) {
+                f[p][i] = ((f[p - 1][i] >> 1) | (f[p - 1][i] << 1) | f[p - 1][i - 1] | f[p - 1][i + 1]) & g[i];
+            }
+        }
+    }
+
+    cout << std::accumulate(f[m].begin(), f[m].end(), 0, [](int x, auto y) -> int { return x + y.count(); }) << endl;
+
+    return 0;
+}