Skip to content

Latest commit

 

History

History
255 lines (201 loc) · 6.66 KB

README.md

File metadata and controls

255 lines (201 loc) · 6.66 KB
Raw

1656. 设计有序流

English Version

题目描述

有 n 个 (id, value) 对，其中 id 是 1 到 n 之间的一个整数，value 是一个字符串。不存在 id 相同的两个 (id, value) 对。

设计一个流，以 任意 顺序获取 n 个 (id, value) 对，并在多次调用时 按 id 递增的顺序 返回一些值。

实现 OrderedStream 类：

  • OrderedStream(int n) 构造一个能接收 n 个值的流，并将当前指针 ptr 设为 1 。
  • String[] insert(int id, String value) 向流中存储新的 (id, value) 对。存储后：
    • 如果流存储有 id = ptr 的 (id, value) 对，则找出从 id = ptr 开始的 最长 id 连续递增序列 ，并 按顺序 返回与这些 id 关联的值的列表。然后，将 ptr 更新为最后那个  id + 1 。

    • 否则，返回一个空列表。

 

示例：

输入
["OrderedStream", "insert", "insert", "insert", "insert", "insert"]
[[5], [3, "ccccc"], [1, "aaaaa"], [2, "bbbbb"], [5, "eeeee"], [4, "ddddd"]]
输出
[null, [], ["aaaaa"], ["bbbbb", "ccccc"], [], ["ddddd", "eeeee"]]

解释
OrderedStream os= new OrderedStream(5);
os.insert(3, "ccccc"); // 插入 (3, "ccccc")，返回 []
os.insert(1, "aaaaa"); // 插入 (1, "aaaaa")，返回 ["aaaaa"]
os.insert(2, "bbbbb"); // 插入 (2, "bbbbb")，返回 ["bbbbb", "ccccc"]
os.insert(5, "eeeee"); // 插入 (5, "eeeee")，返回 []
os.insert(4, "ddddd"); // 插入 (4, "ddddd")，返回 ["ddddd", "eeeee"]

 

提示：

  • 1 <= n <= 1000
  • 1 <= id <= n
  • value.length == 5
  • value 仅由小写字母组成
  • 每次调用 insert 都会使用一个唯一的 id
  • 恰好调用 n 次 insert

解法

Python3

class OrderedStream:
    def __init__(self, n: int):
        self.data = [None] * n
        self.ptr = 0

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

Java

class OrderedStream {
    private String[] data;
    private int ptr;

    public OrderedStream(int n) {
        data = new String[n];
        ptr = 0;
    }

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

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

C++

class OrderedStream {
public:
    vector<string> data;
    int ptr = 0;

    OrderedStream(int n) {
        data.resize(n, "");
    }

    vector<string> insert(int idKey, string value) {
        data[idKey - 1] = value;
        vector<string> ans;
        while (ptr < data.size() && data[ptr] != "") ans.push_back(data[ptr++]);
        return ans;
    }
};

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

Go

type OrderedStream struct {
	data []string
	ptr  int
}

func Constructor(n int) OrderedStream {
	data := make([]string, n)
	return OrderedStream{data, 0}
}

func (this *OrderedStream) Insert(idKey int, value string) []string {
	this.data[idKey-1] = value
	var ans []string
	for this.ptr < len(this.data) && this.data[this.ptr] != "" {
		ans = append(ans, this.data[this.ptr])
		this.ptr++
	}
	return ans
}

/**
 * Your OrderedStream object will be instantiated and called as such:
 * obj := Constructor(n);
 * param_1 := obj.Insert(idKey,value);
 */

TypeScript

class OrderedStream {
    private ptr: number;
    private vals: string[];

    constructor(n: number) {
        this.ptr = 0;
        this.vals = new Array(n);
    }

    insert(idKey: number, value: string): string[] {
        this.vals[idKey - 1] = value;
        const res = [];
        while (this.vals[this.ptr] != null) {
            res.push(this.vals[this.ptr]);
            this.ptr++;
        }
        return res;
    }
}

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

Rust

struct OrderedStream {
    ptr: usize,
    vals: Vec<Option<String>>,
}

/**
 * `&self` means the method takes an immutable reference.
 * If you need a mutable reference, change it to `&mut self` instead.
 */
impl OrderedStream {
    fn new(n: i32) -> Self {
        Self { ptr: 0, vals: vec![None; n as usize] }
    }

    fn insert(&mut self, id_key: i32, value: String) -> Vec<String> {
        self.vals[(id_key - 1) as usize] = Some(value);
        let mut res = Vec::new();
        while self.ptr < self.vals.len() {
            if let Some(s) = &self.vals[self.ptr] {
                res.push(s.clone());
                self.ptr += 1;
            } else {
                break;
            }
        }
        res
    }
}

/**
 * Your OrderedStream object will be instantiated and called as such:
 * let obj = OrderedStream::new(n);
 * let ret_1: Vec<String> = obj.insert(idKey, value);
 */

...