CS-Notes/docs/notes/31. 栈的压入、弹出序列.md
2019-11-02 17:33:10 +08:00

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# 31. 栈的压入弹出序列
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## 题目描述
输入两个整数序列第一个序列表示栈的压入顺序请判断第二个序列是否为该栈的弹出顺序假设压入栈的所有数字均不相等
例如序列 1,2,3,4,5 是某栈的压入顺序序列 4,5,3,2,1 是该压栈序列对应的一个弹出序列 4,3,5,1,2 就不可能是该压栈序列的弹出序列
## 解题思路
使用一个栈来模拟压入弹出操作
```java
public boolean IsPopOrder(int[] pushSequence, int[] popSequence) {
int n = pushSequence.length;
Stack<Integer> stack = new Stack<>();
for (int pushIndex = 0, popIndex = 0; pushIndex < n; pushIndex++) {
stack.push(pushSequence[pushIndex]);
while (popIndex < n && !stack.isEmpty()
&& stack.peek() == popSequence[popIndex]) {
stack.pop();
popIndex++;
}
}
return stack.isEmpty();
}
```
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