add python code

public/py/ch4/huodong/activity_selection.py

@@ -0,0 +1,30 @@
+"""
+活动选择问题 — 贪心算法
+选择最多的不重叠活动
+"""
+
+def activity_selection(start, finish):
+    """贪心选择最早结束的活动"""
+    n = len(start)
+    # 按结束时间排序
+    activities = sorted(zip(start, finish), key=lambda x: x[1])
+
+    selected = [activities[0]]
+    last_finish = activities[0][1]
+
+    for i in range(1, n):
+        if activities[i][0] >= last_finish:
+            selected.append(activities[i])
+            last_finish = activities[i][1]
+
+    return selected
+
+if __name__ == "__main__":
+    start = [1, 3, 0, 5, 8, 5]
+    finish = [2, 4, 6, 7, 9, 9]
+
+    result = activity_selection(start, finish)
+    print("选择的活动 (开始, 结束):")
+    for s, f in result:
+        print(f"  [{s}, {f})")
+    print(f"共 {len(result)} 个活动")