sql injection demo

Author: greyshell

ds_algorithm/heap/concept_heap.py ds_algorithm/heap/demo_heap.pyds_algorithm/heap/concept_heap.py renamed to ds_algorithm/heap/demo_heap.py

@@ -1,7 +1,7 @@
 #!/usr/bin/env python3
 
 # author: greyshell
-# description: learning heap methods
+# description: how to use heap ADT
 
 import heapq
 
@@ -37,6 +37,7 @@ def heap_sort_compact(h):
 # noinspection PyProtectedMember
 def main():
     nums = [12, 7, 11, 15, 35, 17]
+    # take a copy
     test_nums = nums.copy()
     print(f"list: {nums}")
 

ds_algorithm/queue/concept_queue.py

@@ -0,0 +1,35 @@
+#!/usr/bin/env python3
+
+# author: greyshell
+# description: how to use queue ADT
+
+from collections import deque as queue
+
+
+def main():
+    q = queue()
+    # enque: adding items at rear
+    q.append(9)
+    q.append(5)
+    q.append(3)
+    q.append(1)
+
+    # display the queue elements
+    print(f"display the queue elements: {list(q)}")
+
+    # dequeue: deleting items from front
+    data = q.popleft()
+    print(f"item deleted from font: {data}")
+    print(f"display the queue elements: {list(q)}")
+
+    # peek
+    print(f"peek the front: {q[0]}")
+    print(f"peek the rare: {q[-1]}")
+
+    # dequeue at rear
+    data = q.pop()
+    print(f"item deleted from rare: {data}")
+
+
+if __name__ == '__main__':
+    main()

ds_algorithm/queue/demo_queue.py

@@ -0,0 +1,31 @@
+#!/usr/bin/env python3
+
+# author: greyshell
+# description: how to use stack ADT
+
+from collections import deque as stack
+
+
+def main():
+    s = stack()
+    # push: stack grows from right
+    s.append(9)
+    s.append(5)
+    s.append(3)
+    s.append(1)
+
+    # display the stack elements
+    print(f"display the stack elements: {list(s)}")
+
+    # pop: stack shrinks from right
+    data = s.pop()
+    print(f"popped: {data}")
+
+    print(f"display the stack elements: {list(s)}")
+
+    # peek
+    print(f"peek the stack top: {s[-1]}")
+
+
+if __name__ == '__main__':
+    main()