build

docs/chapter_dynamic_programming/dp_problem_features.md

@@ -809,7 +809,26 @@ $$
 === "C"
 
     ```c title="climbing_stairs_constraint_dp.c"
-    [class]{}-[func]{climbingStairsConstraintDP}
+    /* 带约束爬楼梯：动态规划 */
+    int climbingStairsConstraintDP(int n) {
+        if (n == 1 || n == 2) {
+            return 1;
+        }
+        // 初始化 dp 表，用于存储子问题的解
+        int dp[n + 1][3];
+        memset(dp, 0, sizeof(dp));
+        // 初始状态：预设最小子问题的解
+        dp[1][1] = 1;
+        dp[1][2] = 0;
+        dp[2][1] = 0;
+        dp[2][2] = 1;
+        // 状态转移：从较小子问题逐步求解较大子问题
+        for (int i = 3; i <= n; i++) {
+            dp[i][1] = dp[i - 1][2];
+            dp[i][2] = dp[i - 2][1] + dp[i - 2][2];
+        }
+        return dp[n][1] + dp[n][2];
+    }
     ```
 
 === "Zig"