标签：lin push first turn result nat init The list
Given two sequences pushed and popped with distinct values, return true if and only if this could have been the result of a sequence of push and pop operations on an initially empty stack.
Example 1:
Input: pushed = [1,2,3,4,5], popped = [4,5,3,2,1]
Output: true
Explanation: We might do the following sequence:
push(1), push(2), push(3), push(4), pop() -> 4,
push(5), pop() -> 5, pop() -> 3, pop() -> 2, pop() -> 1
Example 2:
Input: pushed = [1,2,3,4,5], popped = [4,3,5,1,2] Output: false Explanation: 1 cannot be popped before 2.
Time: O(N)
class Solution { public boolean validateStackSequences(int[] pushed, int[] popped) { LinkedList<Integer> stack = new LinkedList<>(); int index = 0; for (int num : pushed) { stack.offerFirst(num); while (!stack.isEmpty() && stack.peekFirst() == popped[index]) { stack.pollFirst(); index += 1; } } return stack.isEmpty(); } }
[LC] 946. Validate Stack Sequences
标签：lin push first turn result nat init The list
原文地址：https://www.cnblogs.com/xuanlu/p/13062883.html
