fix:下一个更大的元素

14_刷题/day03/problem_solving_27_01.py

+"""
+下一个更大元素 I
+"""
+from typing import List
+
+
+class Solution:
+    def nextGreaterElement(self, nums1: List[int], nums2: List[int]) -> List[int]:
+        res = []
+        for num in nums1:
+            for index, num2 in enumerate(nums2):
+                if num == num2:
+                    flag = False
+                    for right in range(index + 1, len(nums2)):
+                        if right == len(nums2):
+                            break
+                        if nums2[right] > num2:
+                            res.append(nums2[right])
+                            flag = True
+                            break
+                    if flag:
+                        break
+                    res.append(-1)
+        return res
+
+
+if __name__ == '__main__':
+    result = Solution().nextGreaterElement([4, 1, 2], [1, 3, 4, 2])
+    print(result)

14_刷题/day03/problem_solving_27_02.py

+"""
+下一个更大元素 I
+"""
+from typing import List
+
+
+class Solution:
+    def nextGreaterElement(self, nums1: List[int], nums2: List[int]) -> List[int]:
+        """
+        使用栈解决
+        栈顶元素肯定是比当前元素大的元素,否则取出,stack=[4,3,1] 2在遍历4的时候取出了
+        :param nums1:
+        :param nums2:
+        :return:
+        """
+        stack = []
+        next_map = {}
+        res = []
+
+        # 倒序遍历nums2
+        for num in nums2[::-1]:
+            while stack and stack[-1] < num:
+                stack.pop()
+            next_map[num] = stack[-1] if stack else -1
+            stack.append(num)
+        for num in nums1:
+            res.append(next_map[num])
+        return res
+
+
+if __name__ == '__main__':
+    result = Solution().nextGreaterElement([4, 1, 2], [1, 3, 4, 2])
+    print(result)