2020-06-17

Author: JiayangWu

1442.形成两个异或相等数组的三元组数目/1442-形成两个异或相等数组的三元组数目.py

@@ -0,0 +1,20 @@
+class Solution(object):
+    def countTriplets(self, arr):
+        """
+        :type arr: List[int]
+        :rtype: int
+        """
+        leftXOR = [0 for _ in arr] + [0]
+
+        res = 0
+        
+        for i, x in enumerate(arr):
+            leftXOR[i + 1] = leftXOR[i] ^ x
+
+        for i in range(len(arr) + 1):
+            for j in range(i + 1, len(arr) + 1):
+                for k in range(j + 1, len(arr) + 1):
+                    if leftXOR[i] ^ leftXOR[j] == leftXOR[j] ^ leftXOR[k]:
+                        res += 1
+
+        return res