力扣每日一题2022-08-16简单题：设计有序流

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题目描述

1656.设计有序流

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思路

模拟

对于OrderedStream(int n)，在初始化时创建一个长度为k+1的数组stream，用来存储后续的字符串。由于指针ptr的初始值为1，数组下标是从0开始的，所以使用长度n+1的数组可以使编码更方便。
对于String[] insert(int id, String value)，直接根据题意模拟即可。将stream[id]置为value，如果stream[id]不为空，就将其加入答案，并将ptr+1，知道指针超出边界或stream[id]为空时结束并返回答案。

Python实现

class OrderedStream:

    def __init__(self, n: int):
        self.stream = [""] * (n+1)
        self.ptr = 1


    def insert(self, idKey: int, value: str) -> List[str]:
        self.stream[idKey] = value
        ans = list()
        while self.ptr < len(self.stream) and self.stream[self.ptr]:
            ans.append(self.stream[self.ptr])
            self.ptr += 1
        return ans



# Your OrderedStream object will be instantiated and called as such:
# obj = OrderedStream(n)
# param_1 = obj.insert(idKey,value)
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Java实现

class OrderedStream {

    private String[] stream;
    private int ptr;

    public OrderedStream(int n) {
        stream = new String[n+1];
        ptr = 1;
    }
    
    public List<String> insert(int idKey, String value) {
        stream[idKey] = value;
        List<String> ans = new ArrayList<String>();
        while (ptr < stream.length && stream[ptr] != null) {
            ans.add(stream[ptr]);
            ++ptr;
        }
        return ans;
    }
}

/**
 * Your OrderedStream object will be instantiated and called as such:
 * OrderedStream obj = new OrderedStream(n);
 * List param_1 = obj.insert(idKey,value);
 */
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C++实现

class OrderedStream {
private:
    vector<string> stream;
    int ptr;

public:
    OrderedStream(int n) {
        stream.resize(n+1);
        ptr = 1;
    }
    
    vector<string> insert(int idKey, string value) {
        stream[idKey] = value;
        vector<string> ans;
        while (ptr < stream.size() && !stream[ptr].empty()) {
            ans.push_back(stream[ptr]);
            ++ptr;
        }
        return ans;
    }
};

/**
 * Your OrderedStream object will be instantiated and called as such:
 * OrderedStream* obj = new OrderedStream(n);
 * vector param_1 = obj->insert(idKey,value);
 */
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