leetcode

commit a3fc419862fc9771da68d2c4f1696496c2c0ac59
parent a3293e7b8ec4cb65724351b4ccba5dfeeaf5f46c
Author: Jack Sangdahl <jack@pngu.org>
Date:   Sat, 11 Apr 2026 17:01:05 -0600

3702. longest subsequence with non-zero bitwise xor

Diffstat:
A
longest_subseq_nz_xor.c
 | 
28
++++++++++++++++++++++++++++
A
longest_subseq_nz_xor.py
 | 
26
++++++++++++++++++++++++++

2 files changed, 54 insertions(+), 0 deletions(-)
diff --git a/longest_subseq_nz_xor.c b/longest_subseq_nz_xor.c
@@ -0,0 +1,28 @@
+// 3702. Longest Subsequence With Non-Zero Bitwise XOR
+#include "leetcode.h"
+
+/*
+ * you are given an integer array 'nums'. return the length of the longest
+ * subsequence in 'nums' whose bitwise xor is non zero. if no such subsequence
+ * exists, return 0.
+ */
+
+int longestSubsequence(int *nums, int numsSize) {
+  int sum = 0;
+  bool pos = false;
+  for (int i = 0; i < numsSize; i++) {
+    pos |= (bool)nums[i];
+    sum ^= nums[i];
+  }
+  return pos ? numsSize - !sum : 0;
+}
+
+int main() {
+  int n1[] = {1, 2, 3}, n2[] = {2, 3, 4};
+  int r1 = longestSubsequence(n1, ARRAY_SIZE(n1));
+  int r2 = longestSubsequence(n2, ARRAY_SIZE(n2));
+  printf("%d\n", r1);
+  assert(r1 == 2);
+  printf("%d\n", r2);
+  assert(r2 == 3);
+}
diff --git a/longest_subseq_nz_xor.py b/longest_subseq_nz_xor.py
@@ -0,0 +1,26 @@
+# 3702. Longest Subsequence With Non-Zero Bitwise XOR
+from functools import reduce
+from operator import xor
+from typing import List
+
+"""
+you are given an integer array 'nums'. return the length of the longest
+subsequence in 'nums' whose bitwise xor is non zero. if no such subsequence
+exists, return 0.
+"""
+
+
+class Solution:
+    def longestSubsequence(self, nums: List[int]) -> int:
+        n = len(nums)
+        if max(nums) == 0:
+            return 0
+        if reduce(xor, nums) == 0:
+            return n - 1
+        return n
+
+
+if __name__ == "__main__":
+    obj = Solution()
+    print(obj.longestSubsequence(nums=[1, 2, 3]))
+    print(obj.longestSubsequence(nums=[2, 3, 4]))