Added Solution for 1307. Verbal Arithmetic Puzzel and Updated README.md and README_EN.md

Author: nrhitik

solution/1300-1399/1307.Verbal Arithmetic Puzzle/README.md

@@ -69,6 +69,45 @@
 <!-- 这里可写当前语言的特殊实现逻辑 -->
 
 ```python
+class Solution:
+    def isSolvable(self, words: List[str], result: str) -> bool:
+        words.append(result)
+        rows = len(words)
+        cols = max(map(len, words))
+        letterToDigit = {}
+        usedDigit = [False] * 10
+
+        def dfs(row: int, col: int, summ: int) -> bool:
+            if col == cols:
+                return summ == 0
+            if row == rows:
+                return summ % 10 == 0 and dfs(0, col + 1, summ // 10)
+
+            word = words[row]
+            if col >= len(word):
+                return dfs(row + 1, col, summ)
+
+            letter = word[~col]
+            sign = -1 if row == rows - 1 else 1
+
+            if letter in letterToDigit and (
+                letterToDigit[letter] > 0 or col < len(word) - 1
+            ):
+                return dfs(row + 1, col, summ + sign * letterToDigit[letter])
+
+            for digit, used in enumerate(usedDigit):
+                if not used and (digit > 0 or col < len(word) - 1):
+                    letterToDigit[letter] = digit
+                    usedDigit[digit] = True
+                    if dfs(row + 1, col, summ + sign * digit):
+                        return True
+                    usedDigit[digit] = False
+                    if letter in letterToDigit:
+                        del letterToDigit[letter]
+
+            return False
+
+        return dfs(0, 0, 0)
 
 ```
 

solution/1300-1399/1307.Verbal Arithmetic Puzzle/README_EN.md

@@ -60,6 +60,45 @@ Note that two different characters cannot map to the same digit.
 ### **Python3**
 
 ```python
+class Solution:
+    def isSolvable(self, words: List[str], result: str) -> bool:
+        words.append(result)
+        rows = len(words)
+        cols = max(map(len, words))
+        letterToDigit = {}
+        usedDigit = [False] * 10
+
+        def dfs(row: int, col: int, summ: int) -> bool:
+            if col == cols:
+                return summ == 0
+            if row == rows:
+                return summ % 10 == 0 and dfs(0, col + 1, summ // 10)
+
+            word = words[row]
+            if col >= len(word):
+                return dfs(row + 1, col, summ)
+
+            letter = word[~col]
+            sign = -1 if row == rows - 1 else 1
+
+            if letter in letterToDigit and (
+                letterToDigit[letter] > 0 or col < len(word) - 1
+            ):
+                return dfs(row + 1, col, summ + sign * letterToDigit[letter])
+
+            for digit, used in enumerate(usedDigit):
+                if not used and (digit > 0 or col < len(word) - 1):
+                    letterToDigit[letter] = digit
+                    usedDigit[digit] = True
+                    if dfs(row + 1, col, summ + sign * digit):
+                        return True
+                    usedDigit[digit] = False
+                    if letter in letterToDigit:
+                        del letterToDigit[letter]
+
+            return False
+
+        return dfs(0, 0, 0)
 
 ```
 

solution/1300-1399/1307.Verbal Arithmetic Puzzle/Solution.py

@@ -0,0 +1,39 @@
+class Solution:
+    def isSolvable(self, words: List[str], result: str) -> bool:
+        words.append(result)
+        rows = len(words)
+        cols = max(map(len, words))
+        letterToDigit = {}
+        usedDigit = [False] * 10
+
+        def dfs(row: int, col: int, summ: int) -> bool:
+            if col == cols:
+                return summ == 0
+            if row == rows:
+                return summ % 10 == 0 and dfs(0, col + 1, summ // 10)
+
+            word = words[row]
+            if col >= len(word):
+                return dfs(row + 1, col, summ)
+
+            letter = word[~col]
+            sign = -1 if row == rows - 1 else 1
+
+            if letter in letterToDigit and (
+                letterToDigit[letter] > 0 or col < len(word) - 1
+            ):
+                return dfs(row + 1, col, summ + sign * letterToDigit[letter])
+
+            for digit, used in enumerate(usedDigit):
+                if not used and (digit > 0 or col < len(word) - 1):
+                    letterToDigit[letter] = digit
+                    usedDigit[digit] = True
+                    if dfs(row + 1, col, summ + sign * digit):
+                        return True
+                    usedDigit[digit] = False
+                    if letter in letterToDigit:
+                        del letterToDigit[letter]
+
+            return False
+
+        return dfs(0, 0, 0)