diff --git a/2022_binary_tree.cpp b/2022_binary_tree.cpp
new file mode 100644
index 0000000..eb824ad
--- /dev/null
+++ b/2022_binary_tree.cpp
@@ -0,0 +1,35 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#define MaxSize 100
+
+typedef struct {
+    int Sqlistdata[MaxSize];
+    int num;
+} Sqlist;
+
+bool T = true;
+void inorder(Sqlist a, int i) {
+    if (i >= a.num || a.Sqlistdata[i] == -1 || !T) {
+        return;
+    }
+    int k = a.Sqlistdata[i];
+    inorder(a, i * 2 + 1);
+    if (k < a.Sqlistdata[i * 2 + 1]) {
+        T = false;
+        return;
+    }
+    inorder(a, i * 2 + 2);
+}
+
+int main() {
+    Sqlist s = Sqlist();
+    int a[] = {4, 2, 6, 1, 3, 5, 7};  //高度为3的满二叉排序树
+    s.num = 7;
+    for (int i = 0; i < s.num; i++) {
+        s.Sqlistdata[i] = a[i];
+    }
+    inorder(s, 0);
+    printf(T ? "是二叉搜索树" : "不是二叉搜索树");
+    return 0;
+}