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logger-rate-limiter

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Logger Rate Limiter – LeetCode 359

Problem

Description

Design a logger system that receive stream of messages along with its timestamps, each message should be printed if and only if it is not printed in the last 10 seconds.

Given a message and a timestamp (in seconds granularity), return true if the message should be printed in the given timestamp, otherwise returns false.

It is possible that several messages arrive roughly at the same time.

Example

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Logger logger = new Logger();

// logging string "foo" at timestamp 1
logger.shouldPrintMessage(1, "foo"); returns true; 

// logging string "bar" at timestamp 2
logger.shouldPrintMessage(2,"bar"); returns true;

// logging string "foo" at timestamp 3
logger.shouldPrintMessage(3,"foo"); returns false;

// logging string "bar" at timestamp 8
logger.shouldPrintMessage(8,"bar"); returns false;

// logging string "foo" at timestamp 10
logger.shouldPrintMessage(10,"foo"); returns false;

// logging string "foo" at timestamp 11
logger.shouldPrintMessage(11,"foo"); returns true;

Answer

Original

Code

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class Logger {
public:
    Logger() {}
    
    bool shouldPrintMessage(int timestamp, string message) {
		if(!m.count(message) || timestamp - m[message] >= 10){
			m[message] = timestamp;
			return true;
		} else
			return false;
    }

private:
	unordered_map<string, int> m;
};

思路

简单的用hashmap去存储信息，时间复杂度$O(1)$，空间复杂度$O(n)$。

Better

还没看到更好的思路。