leetcode

commit 64ccda3aff7e186e03bdc963a8ab110d2bc01e19
parent 59613ec9d3a899b43dd9c788cb1c0d14719eff76
Author: Jack Sangdahl <jack@pngu.org>
Date:   Mon, 28 Jul 2025 20:58:11 -0600

2411. smallest subarrays with maximum bitwise or

Diffstat:
A
smallest_subarr_max_or.c
 | 
41
+++++++++++++++++++++++++++++++++++++++++
A
smallest_subarr_max_or.py
 | 
35
+++++++++++++++++++++++++++++++++++

2 files changed, 76 insertions(+), 0 deletions(-)
diff --git a/smallest_subarr_max_or.c b/smallest_subarr_max_or.c
@@ -0,0 +1,41 @@
+// 2411. Smallest Subarrays With Maximum Bitwise OR
+#include "leetcode.h"
+
+/*
+ * you are given a 0-indexed array 'nums' of length 'n', consisting of
+ * non-negative integers. for each index 'i' from 0 to 'n - 1', you must
+ * determine the size of the minimum sized non-empty subarray of 'nums' starting
+ * at 'i' that has the maximum possible bitwise or. the bitwosee or of an array
+ * is the bitwise or of all the numbers in it. return an integer array 'answer'
+ * of size 'n' where 'answer[i]' is the length of the minimum sized subarray
+ * starting at 'i' with maximum bitwise or. a subarray is a contiguous non-empty
+ * sequence of elements within an array.
+ */
+
+int *smallestSubarrays(int *nums, int numsSize, int *returnSize) {
+  int prev[30], *ans = (int *)malloc(numsSize * sizeof(int));
+  memset(ans, 1, numsSize * sizeof(int));
+  *returnSize = numsSize;
+  for (int i = numsSize - 1; i >= 0; --i)
+    for (int j = 0; j < 30; ++j) {
+      if (nums[i] & (1 << j))
+        prev[j] = i;
+      ans[i] = fmax(ans[i], prev[j] - i + 1);
+    }
+  return ans;
+}
+
+int main() {
+  int n1[] = {1, 0, 2, 1, 3}, rs1;
+  int n2[] = {1, 2}, rs2;
+  int *sb1 = smallestSubarrays(n1, ARRAY_SIZE(n1), &rs1);
+  int *sb2 = smallestSubarrays(n2, ARRAY_SIZE(n2), &rs2);
+  for (int i = 0; i < rs1; i++)
+    printf("%d ", sb1[i]); // expect: 3 3 2 2 1
+  printf("\n");
+  for (int i = 0; i < rs2; i++)
+    printf("%d ", sb2[i]); // expect: 2 1
+  printf("\n");
+  free(sb1);
+  free(sb2);
+}
diff --git a/smallest_subarr_max_or.py b/smallest_subarr_max_or.py
@@ -0,0 +1,35 @@
+# 2411. Smallest Subarrays With Maximum Bitwise OR
+
+"""
+you are given a 0-indexed array 'nums' of length 'n', consisting of
+non-negative integers. for each index 'i' from 0 to 'n - 1', you must
+determine the size of the minimum sized non-empty subarray of 'nums' starting
+at 'i' that has the maximum possible bitwise or. the bitwosee or of an array
+is the bitwise or of all the numbers in it. return an integer array 'answer'
+of size 'n' where 'answer[i]' is the length of the minimum sized subarray
+starting at 'i' with maximum bitwise or. a subarray is a contiguous non-empty
+sequence of elements within an array.
+"""
+
+
+class Solution(object):
+    def smallestSubarrays(self, nums):
+        """
+        :type nums: List[int]
+        :rtype: List[int]
+        """
+        prev = [0] * 32
+        n = len(nums)
+        ans = [0] * n
+        for i in range(n - 1, -1, -1):
+            for j in range(32):
+                if nums[i] & (1 << j):
+                    prev[j] = i
+            ans[i] = max(1, max(prev) - i + 1)
+        return ans
+
+
+if __name__ == "__main__":
+    obj = Solution()
+    print(obj.smallestSubarrays(nums=[1, 0, 2, 1, 3]))
+    print(obj.smallestSubarrays(nums=[1, 2]))