496. Next Greater Element I.

    - Language: Python.
    - Time complexity: O(n * m).
    - Space complexity: O(1).
    - Method: Brute Force.

Author: welder87

python_solutions/lc_496_next_greater_element_1/__init__.py

@@ -0,0 +1,14 @@
+class Solution:
+    def nextGreaterElement(self, nums1: list[int], nums2: list[int]) -> list[int]:
+        # Time complexity: O(n * m). Space complexity: O(1).
+        ans = [-1] * len(nums1)
+        for idx, num in enumerate(nums1):
+            cur, val = None, -1
+            for nxt_num in nums2:
+                if cur is None and num == nxt_num:
+                    cur = nxt_num
+                elif cur is not None and nxt_num > cur:
+                    val = nxt_num
+                    break
+            ans[idx] = val
+        return ans

python_solutions/lc_496_next_greater_element_1/lc_496_next_greater_element_1.py

@@ -0,0 +1,32 @@
+import pytest
+
+from lc_496_next_greater_element_1.lc_496_next_greater_element_1 import Solution
+
+test_cases = (
+    # preset cases
+    ([4, 1, 2], [1, 3, 4, 2], [-1, 3, -1]),
+    ([2, 4], [1, 2, 3, 4], [3, -1]),
+    # common cases
+    ([9, 0, 24, 17], [11, 9, 4, 0, 20, 24, 17, 35], [20, 20, 35, 35]),
+    ([9, 0, 24, 35], [11, 35, 4, 0, 20, 24, 17, 9], [-1, 20, -1, -1]),
+    ([9, 0, 24, 35, 11], [11, 35, 4, 9, 0, 20, 17, 24], [20, 20, -1, -1, 35]),
+    # corner cases
+    ([1], [1], [-1]),
+    ([2, 4], [2, 4], [4, -1]),
+)
+
+
+@pytest.mark.parametrize(("nums1", "nums2", "ans"), test_cases)
+def test_success_v0(
+    nums1: list[int],
+    nums2: list[int],
+    ans: list[int],
+    solution: Solution,
+):
+    res = solution.nextGreaterElement(nums1, nums2)
+    assert res == ans
+
+
+@pytest.fixture
+def solution() -> Solution:
+    return Solution()