leetcode

commit 000be985481665195260d7e0c20c76e1607c339b
parent b5c87065a4c77cc960dd1f852ccd6aba1185e11f
Author: Jack Sangdahl <jack@pngu.org>
Date:   Mon, 13 Oct 2025 21:28:30 -0600

3349. adjacent increasing subarrays detectiong 1

Diffstat:
A
adjacent_subarr_detect1.c
 | 
35
+++++++++++++++++++++++++++++++++++
A
adjacent_subarr_detect1.py
 | 
37
+++++++++++++++++++++++++++++++++++++

2 files changed, 72 insertions(+), 0 deletions(-)
diff --git a/adjacent_subarr_detect1.c b/adjacent_subarr_detect1.c
@@ -0,0 +1,35 @@
+// 3349. Adjacent Increasing Subarrays Detection I
+#include "leetcode.h"
+
+/*
+ * given an array 'nums' of 'n' integers and an integer 'k', determine whther
+ * there exist two adjacent subarrays of length 'k' such that both subarrays are
+ * strictly increasing. specifically, check if there are two subarrays starting
+ * at indices 'a' and 'b' ('a < b') where both subarrays 'nums[a..a + k - 1]'
+ * and 'nums[b..b + k - 1]' are strictly increasing, and the subarrays must be
+ * adjacent, meaning 'b = a + k'. return true if it is possible to find two such
+ * subarrays and 'false'  otherwise.
+ */
+
+bool hasIncreasingSubarrays(int *nums, int numsSize, int k) {
+  int inc = 1, prev = 0, max_len = 0;
+  for (int i = 1; i < numsSize; i++) {
+    if (nums[i] > nums[i - 1])
+      inc++;
+    else {
+      prev = inc;
+      inc = 1;
+    }
+    max_len = fmax(max_len, fmax(inc >> 1, fmin(prev, inc)));
+    if (max_len >= k)
+      return true;
+  }
+  return false;
+}
+
+int main() {
+  int n1[] = {2, 5, 7, 8, 9, 2, 3, 4, 3, 1},
+      n2[] = {1, 2, 3, 4, 4, 4, 4, 5, 6, 7};
+  printf("%d\n", hasIncreasingSubarrays(n1, ARRAY_SIZE(n1), 3)); // expect: 1
+  printf("%d\n", hasIncreasingSubarrays(n2, ARRAY_SIZE(n2), 5)); // expect: 0
+}
diff --git a/adjacent_subarr_detect1.py b/adjacent_subarr_detect1.py
@@ -0,0 +1,37 @@
+# 3349. Adjacent Increasing Subarrays Detection I
+
+"""
+given an array 'nums' of 'n' integers and an integer 'k', determine whther
+there exist two adjacent subarrays of length 'k' such that both subarrays are
+strictly increasing. specifically, check if there are two subarrays starting
+at indices 'a' and 'b' ('a < b') where both subarrays 'nums[a..a + k - 1]'
+and 'nums[b..b + k - 1]' are strictly increasing, and the subarrays must be
+adjacent, meaning 'b = a + k'. return true if it is possible to find two such
+subarrays and 'false'  otherwise.
+"""
+
+
+class Solution(object):
+    def hasIncreasingSubarrays(self, nums, k):
+        """
+        :type nums: List[int]
+        :type k: int
+        :rtype: bool
+        """
+        inc, prev, max_len = 1, 0, 0
+        for i in range(1, len(nums)):
+            if nums[i] > nums[i - 1]:
+                inc += 1
+            else:
+                prev = inc
+                inc = 1
+            max_len = max(max_len, max(inc >> 1, min(prev, inc)))
+            if max_len >= k:
+                return True
+        return False
+
+
+if __name__ == "__main__":
+    obj = Solution()
+    print(obj.hasIncreasingSubarrays(nums=[2, 5, 7, 8, 9, 2, 3, 4, 3, 1], k=3))
+    print(obj.hasIncreasingSubarrays(nums=[1, 2, 3, 4, 4, 4, 4, 5, 6, 7], k=5))