Update 0860.柠檬水找零.md

problems/0860.柠檬水找零.md

@@ -164,24 +164,39 @@ class Solution {
 ```python
 class Solution:
     def lemonadeChange(self, bills: List[int]) -> bool:
-        five, ten = 0, 0
+        five = 0
+        ten = 0
+        twenty = 0
+        
         for bill in bills:
+            # 情况一：收到5美元
             if bill == 5:
                 five += 1
-            elif bill == 10:
+            
-                if five < 1: return False
+            # 情况二：收到10美元
-                five -= 1
+            if bill == 10:
+                if five <= 0:
+                    return False
                 ten += 1
-            else:
-                if ten > 0 and five > 0:
-                    ten -= 1
                 five -= 1
-                elif five > 2:
+            
+            # 情况三：收到20美元
+            if bill == 20:
+                # 先尝试使用10美元和5美元找零
+                if five > 0 and ten > 0:
+                    five -= 1
+                    ten -= 1
+                    #twenty += 1
+                # 如果无法使用10美元找零，则尝试使用三张5美元找零
+                elif five >= 3:
                     five -= 3
+                    #twenty += 1
                 else:
                     return False
+        
         return True
 
+
 ```
 
 ### Go