Create cells-with-odd-values-in-a-matrix.py

Author: kamyu104

Python/cells-with-odd-values-in-a-matrix.py

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+# Time:  O(n + m)
+# Space: O(n + m)
+
+class Solution(object):
+    def oddCells(self, n, m, indices):
+        """
+        :type n: int
+        :type m: int
+        :type indices: List[List[int]]
+        :rtype: int
+        """
+        row, col = [0]*n, [0]*m
+        for r, c in indices:
+            row[r] ^= 1
+            col[c] ^= 1
+        row_sum, col_sum = sum(row), sum(col)
+        return row_sum*m+col_sum*n-2*row_sum*col_sum
+
+
+# Time:  O(n + m)
+# Space: O(n + m)
+import collections
+import itertools
+
+
+class Solution2(object):
+    def oddCells(self, n, m, indices):
+        """
+        :type n: int
+        :type m: int
+        :type indices: List[List[int]]
+        :rtype: int
+        """
+        fn = lambda x: sum(count&1 for count in collections.Counter(x).itervalues())
+        row_sum, col_sum = map(fn, itertools.izip(*indices))
+        return row_sum*m+col_sum*n-2*row_sum*col_sum