diff --git a/CTDL-GT/Tut7.cpp b/CTDL-GT/Tut7.cpp
new file mode 100644
index 0000000..3f8df69
--- /dev/null
+++ b/CTDL-GT/Tut7.cpp
@@ -0,0 +1,78 @@
+#include <cmath>
+#include <iostream>
+
+using namespace std;
+
+template <class T>
+void printHeap(T *heap, int cnt, int pos)
+{
+    if (cnt < 1)
+        return;
+    if (pos >= cnt) {
+        for (int i = 1; i <= log(pos + 1) / log(2); ++i)
+            cout << "\t";
+        cout << "NULL" << endl;
+        return;
+    }
+    printHeap(heap, cnt, 2 * pos + 2);
+    for (int i = 1; i <= log(pos + 1) / log(2); ++i)
+        cout << "\t";
+    cout << heap[pos] << endl;
+    printHeap(heap, cnt, 2 * pos + 1);
+}
+
+bool IsMaxHeap(int *arr, int size)
+{
+    for (int i = size - 1; i > 0; --i) {
+        if (arr[i] > arr[(i - 1) / 2])
+            return false;
+    }
+    return true;
+}
+
+void reheapDown(int *&maxHeap, int pos, int size)
+{
+    if (2 * pos + 1 >= size)
+        return;
+    int posMax = 2 * pos + 1;
+    if (2 * pos + 2 < size) {
+        if (maxHeap[2 * pos + 2] > maxHeap[posMax]) {
+            posMax = 2 * pos + 2;
+        }
+    }
+    if (maxHeap[pos] < maxHeap[posMax]) {
+        swap(maxHeap[pos], maxHeap[posMax]);
+        reheapDown(maxHeap, posMax, size);
+    }
+}
+
+bool DeleteHeapNode(int *&maxHeap, int delPosition, int &size, int &dataOut)
+{
+    if (delPosition < 0 || delPosition >= size)
+        return false;
+    dataOut = maxHeap[delPosition];
+    maxHeap[delPosition] = maxHeap[size - 1];
+    --size;
+    reheapDown(maxHeap, delPosition, size);
+}
+
+int main()
+{
+    int maxHeap[6] = {1200, 523, 1001, 321, 14, 131};
+    int *test1 = new int[8] {77, 60, 35, 45, 56, 4, 34, 22};
+    int test2[9] = {9, 8, 4, 7, 5, 2, 3, 1, 6};
+    printHeap(test1, 8, 0);
+    printHeap(test2, 9, 0);
+    if (IsMaxHeap(test1, 8))
+        cout << "True" << endl;
+    else
+        cout << "False" << endl;
+    int out;
+    int size = 8;
+    DeleteHeapNode(test1, 0, size, out);
+    if (DeleteHeapNode(test1, 0, size, out)) {
+        cout << size << "\t" << out << endl;
+    }
+    printHeap(test1, size, 0);
+    return 0;
+}