开始计概A下半学期。

cs101/2025mid/exam_2025mid_08_wall_dp.cpp

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+#include <iostream>
+
+constexpr int MAX_N = 1000001, MOD = 10000;
+
+/// dp[0][i]: 长方形；dp[1][i]: 阶梯型，i 为短边长
+long long dp[2][MAX_N];
+
+void init_dp() {
+    dp[0][0] = 1;
+    dp[0][1] = 1;
+    dp[0][2] = 2;
+    dp[1][0] = 0;
+    dp[1][1] = 1;
+    dp[1][2] = 2;
+    for (int i = 3; i < MAX_N; i++) {
+        dp[0][i] = (dp[0][i - 1] + dp[0][i - 2] + dp[1][i - 2] * 2) % MOD;
+        dp[1][i] = (dp[0][i - 1] + dp[1][i - 1]) % MOD;
+    }
+}
+
+void log_dp(int n) {
+    for (int i = 1; i <= n; i++) {
+        std::clog << dp[0][i] << ' ';
+    }
+    std::clog << std::endl;
+    for (int i = 1; i <= n; i++) {
+        std::clog << dp[1][i] << ' ';
+    }
+    std::clog << std::endl;
+}
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    std::cin.tie(nullptr);
+
+    init_dp();
+    int n;
+    std::cin >> n;
+    std::cout << dp[0][n] % MOD << std::endl;;
+    log_dp(n);
+
+    return 0;
+}