feat(0682_baseball-game): add py3 soln

0682_baseball-game/README.md

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+You are keeping score for a baseball game with strange rules. The game consists of several rounds, where the scores of past rounds may affect future rounds' scores.
+
+At the beginning of the game, you start with an empty record. You are given a list of strings `ops`, where `ops[i]` is the `ith` operation you must apply to the record and is one of the following:
+
+1.  An integer `x` - Record a new score of `x`.
+2.  `"+"` - Record a new score that is the sum of the previous two scores. It is guaranteed there will always be two previous scores.
+3.  `"D"` - Record a new score that is double the previous score. It is guaranteed there will always be a previous score.
+4.  `"C"` - Invalidate the previous score, removing it from the record. It is guaranteed there will always be a previous score.
+
+Return _the sum of all the scores on the record_.
+
+**Example 1:**
+
+    Input: ops = ["5","2","C","D","+"]
+    Output: 30
+    Explanation:
+    "5" - Add 5 to the record, record is now [5].
+    "2" - Add 2 to the record, record is now [5, 2].
+    "C" - Invalidate and remove the previous score, record is now [5].
+    "D" - Add 2 * 5 = 10 to the record, record is now [5, 10].
+    "+" - Add 5 + 10 = 15 to the record, record is now [5, 10, 15].
+    The total sum is 5 + 10 + 15 = 30.
+    
+
+**Example 2:**
+
+    Input: ops = ["5","-2","4","C","D","9","+","+"]
+    Output: 27
+    Explanation:
+    "5" - Add 5 to the record, record is now [5].
+    "-2" - Add -2 to the record, record is now [5, -2].
+    "4" - Add 4 to the record, record is now [5, -2, 4].
+    "C" - Invalidate and remove the previous score, record is now [5, -2].
+    "D" - Add 2 * -2 = -4 to the record, record is now [5, -2, -4].
+    "9" - Add 9 to the record, record is now [5, -2, -4, 9].
+    "+" - Add -4 + 9 = 5 to the record, record is now [5, -2, -4, 9, 5].
+    "+" - Add 9 + 5 = 14 to the record, record is now [5, -2, -4, 9, 5, 14].
+    The total sum is 5 + -2 + -4 + 9 + 5 + 14 = 27.
+    
+
+**Example 3:**
+
+    Input: ops = ["1"]
+    Output: 1
+    
+
+**Constraints:**
+
+*   `1 <= ops.length <= 1000`
+*   `ops[i]` is `"C"`, `"D"`, `"+"`, or a string representing an integer in the range `[-3 * 104, 3 * 104]`.
+*   For operation `"+"`, there will always be at least two previous scores on the record.
+*   For operations `"C"` and `"D"`, there will always be at least one previous score on the record.

0682_baseball-game/python3/solution.py

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+from collections import deque
+
+class Solution:
+    def calPoints(self, ops: List[str]) -> int:
+        d = deque()
+        
+        for _, op in enumerate(ops):
+            if op == "C":
+                d.pop()
+            elif op == "D":
+                d.append(d[-1] * 2)
+            elif op == "+":
+                d.append(d[-1] + d[-2])
+            else:
+                d.append(int(op))
+        
+        total = 0
+        while len(d) > 0:
+            total += d.pop()
+        
+        return total