leetcode

commit 7d9f4fd9a9e5b846a9fe7e3ff6c794722d045eb6
parent 91183f92ac13aa4ca9cc6d18629483aa9762b54e
Author: Jack Sangdahl <jack@pngu.org>
Date:   Mon,  3 Nov 2025 17:47:09 -0700

693. binary number with alternating bits

Diffstat:
A
binary_num_alter_bits.c
 | 
18
++++++++++++++++++
A
binary_num_alter_bits.py
 | 
23
+++++++++++++++++++++++

2 files changed, 41 insertions(+), 0 deletions(-)
diff --git a/binary_num_alter_bits.c b/binary_num_alter_bits.c
@@ -0,0 +1,18 @@
+// 693. Binary Number with Alternating Bits
+#include "leetcode.h"
+
+/*
+ * given a positive integer, check whether it has alternating bits: namely if
+ * two adjacent bits will always have different values
+ */
+
+bool hasAlternatingBits(int n) {
+  long long int x = n ^ (n >> 1);
+  return !(x & (x + 1));
+}
+
+int main() {
+  printf("%d\n", hasAlternatingBits(5));  // expect: 1
+  printf("%d\n", hasAlternatingBits(7));  // expect: 0
+  printf("%d\n", hasAlternatingBits(11)); // expect: 0
+}
diff --git a/binary_num_alter_bits.py b/binary_num_alter_bits.py
@@ -0,0 +1,23 @@
+# 693. Binary Number with Alternating Bits
+
+"""
+given a positive integer, check whether it has alternating bits: namely if
+two adjacent bits will always have different values
+"""
+
+
+class Solution(object):
+    def hasAlternatingBits(self, n):
+        """
+        :type n: int
+        :rtype: bool
+        """
+        x = n ^ (n >> 1)
+        return (x & (x + 1)) == 0
+
+
+if __name__ == "__main__":
+    obj = Solution()
+    print(obj.hasAlternatingBits(5))
+    print(obj.hasAlternatingBits(7))
+    print(obj.hasAlternatingBits(11))