2021-03-09

JiayangWu · JiayangWu · commit db1db7d976d3 · 2021-03-09T22:12:59.000-05:00
diff --git a/1556.千位分隔数/1556-千位分隔数.py b/1556.千位分隔数/1556-千位分隔数.py
@@ -4,10 +4,13 @@ def thousandSeparator(self, n):
         :type n: int
         :rtype: str
         """
-        s = str(n)[::-1]
         res = ""
-        for i in range(len(s)):
-            res += s[i]
-            if i % 3 == 2 and i != len(s) - 1:
+        cnt = 0
+        for digit in str(n)[::-1]:
+            res += digit
+            cnt += 1
+            if cnt == 3:
+                cnt = 0
                 res += "."
-        return res[::-1] 
+
+        return res[::-1].strip(".")
diff --git a/1582.二进制矩阵中的特殊位置/1582-二进制矩阵中的特殊位置.py b/1582.二进制矩阵中的特殊位置/1582-二进制矩阵中的特殊位置.py
@@ -0,0 +1,12 @@
+class Solution(object):
+    def numSpecial(self, mat):
+        """
+        :type mat: List[List[int]]
+        :rtype: int
+        """
+        # 找出所有满足条件的行和列
+        possible_rows = [i for i, row in enumerate(mat) if sum(row) == 1]
+        possible_cols = [i for i, col in enumerate(zip(*mat)) if sum(col) == 1]
+        
+        # 在满足条件的行和列里统计值为1的点
+        return sum([mat[i][j] for i in possible_rows for j in possible_cols])
