leetcode

commit 2d4d6db5843b264b91ceec6dbb179e6050fd1e74
parent 132e2dca4c2cd33e3e8a4385c6e247ad1221947b
Author: Jack Sangdahl <jack@pngu.org>
Date:   Fri, 26 Dec 2025 20:57:53 -0700

1486. xor operation in an array

Diffstat:
A
xor_op_in_arr.c
 | 
34
++++++++++++++++++++++++++++++++++
A
xor_op_in_arr.py
 | 
27
+++++++++++++++++++++++++++

2 files changed, 61 insertions(+), 0 deletions(-)
diff --git a/xor_op_in_arr.c b/xor_op_in_arr.c
@@ -0,0 +1,34 @@
+// 1486. XOR Operation in an Array
+#include "leetcode.h"
+
+/*
+ * you are given an integer 'n' and an integer 'start'. define an array 'nums'
+ * where 'nums[i] = star + 2 * i' and 'n == nums.length'. return bitwise xor of
+ * all elements of 'nums'.
+ */
+
+int xor_b(int n, int start) {
+  if (!(n % 2))
+    return (n / 2) & 1;
+  else
+    return ((n / 2) & 1) ^ (start + n - 1);
+}
+
+int xor_a(int n, int start) {
+  if (start & 1)
+    return (start - 1) ^ xor_b(n + 1, start - 1);
+  else
+    return xor_b(n, start);
+}
+
+int xorOperation(int n, int start) {
+  int ans = 2 * xor_a(n, start / 2);
+  if (n & start & 1)
+    ans++;
+  return ans;
+}
+
+int main() {
+  printf("%d\n", xorOperation(5, 0)); // expect: 8
+  printf("%d\n", xorOperation(4, 3)); // expect: 8
+}
diff --git a/xor_op_in_arr.py b/xor_op_in_arr.py
@@ -0,0 +1,27 @@
+# 1486. XOR Operation in an Array
+
+"""
+you are given an integer 'n' and an integer 'start'. define an array 'nums'
+where 'nums[i] = star + 2  i' and 'n == nums.length'. return bitwise xor of
+all elements of 'nums'.
+"""
+
+
+class Solution(object):
+    def xorOperation(self, n, start):
+        """
+        :type n: int
+        :type start: int
+        :rtype: int
+        """
+        ans = 0
+        nums = [start + i * 2 for i in range(n)]
+        for i in nums:
+            ans ^= i
+        return ans
+
+
+if __name__ == "__main__":
+    obj = Solution()
+    print(obj.xorOperation(n=5, start=0))
+    print(obj.xorOperation(n=4, start=3))