Exclusive Time of Functions LeetCode Solution

Last updated on October 5th, 2024 at 04:50 pm

Here, We see Exclusive Time of Functions LeetCode Solution. This Leetcode problem is done in many programming languages like C++, Java, JavaScript, Python, etc. with different approaches.

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Exclusive Time of Functions LeetCode Solution

Exclusive Time of Functions LeetCode Solution

Problem Statement

On a single-threaded CPU, we execute a program containing n functions. Each function has a unique ID between 0 and n-1.

Function calls are stored in a call stack: when a function call starts, its ID is pushed onto the stack, and when a function call ends, its ID is popped off the stack. The function whose ID is at the top of the stack is the current function being executed. Each time a function starts or ends, we write a log with the ID, whether it started or ended, and the timestamp.

You are given a list logs, where logs[i] represents the ith log message formatted as a string “{function_id}:{“start” | “end”}:{timestamp}”. For example, “0:start:3” means a function call with function ID 0 started at the beginning of timestamp 3, and "1:end:2" means a function call with function ID 1 ended at the end of timestamp 2. Note that a function can be called multiple times, possibly recursively.

A function’s exclusive time is the sum of execution times for all function calls in the program. For example, if a function is called twice, one call executing for 2 time units and another call executing for 1 time unit, the exclusive time is 2 + 1 = 3.

Return the exclusive time of each function in an array, where the value at the ith index represents the exclusive time for the function with ID i.

Example 1:

diag1b

Input: n = 2, logs = [“0:start:0″,”1:start:2″,”1:end:5″,”0:end:6”]
Output: [3,4]
Explanation:
Function 0 starts at the beginning of time 0, then it executes 2 for units of time and reaches the end of time 1.
Function 1 starts at the beginning of time 2, executes for 4 units of time, and ends at the end of time 5.
Function 0 resumes execution at the beginning of time 6 and executes for 1 unit of time. So function 0 spends 2 + 1 = 3 units of total time executing, and function 1 spends 4 units of total time executing.

Example 2:
Input: n = 1, logs = [“0:start:0″,”0:start:2″,”0:end:5″,”0:start:6″,”0:end:6″,”0:end:7”]
Output: [8]
Explanation:
Function 0 starts at the beginning of time 0, executes for 2 units of time, and recursively calls itself.
Function 0 (recursive call) starts at the beginning of time 2 and executes for 4 units of time.
Function 0 (initial call) resumes execution then immediately calls itself again.
Function 0 (2nd recursive call) starts at the beginning of time 6 and executes for 1 unit of time.
Function 0 (initial call) resumes execution at the beginning of time 7 and executes for 1 unit of time. So function 0 spends 2 + 4 + 1 + 1 = 8 units of total time executing.

Example 3:
Input: n = 2, logs = [“0:start:0″,”0:start:2″,”0:end:5″,”1:start:6″,”1:end:6″,”0:end:7”]
Output: [7,1]
Explanation:
Function 0 starts at the beginning of time 0, executes for 2 units of time, and recursively calls itself.
Function 0 (recursive call) starts at the beginning of time 2 and executes for 4 units of time.
Function 0 (initial call) resumes execution then immediately calls function 1.
Function 1 starts at the beginning of time 6, executes 1 unit of time, and ends at the end of time 6.
Function 0 resumes execution at the beginning of time 6 and executes for 2 units of time. So function 0 spends 2 + 4 + 1 = 7 units of total time executing, and function 1 spends 1 unit of total time executing.

1. Exclusive Time of Functions LeetCode Solution C++

class Solution {
public:
    vector<int> exclusiveTime(int n, vector<string>& logs) {
        vector<int> ans(n);
        stack<pair<int,int>> cur;
        int prevTime = 0;
        for (auto& s : logs){
            int num = stoi(s.substr(0, s.find(':')));
            int time = stoi(s.substr(s.rfind(':') + 1));
            if (s.find('e') != -1){
                ans[num] += time - prevTime + 1;
                cur.pop();
                prevTime = time + 1;
            }
            else{
                if (!cur.empty()) ans[cur.top().first] += time - prevTime ;
                cur.push({num, time});
                prevTime = time;
            }
        }
        return ans;
    }
};

2. Exclusive Time of Functions LeetCode Solution Java

class Solution {
    public int[] exclusiveTime(int n, List<String> logs) {
        int[] result = new int[n];
        if (n == 0 || logs == null || logs.size() == 0) {
            return result;
        }
        Deque<Integer> stack = new ArrayDeque<>();
        int prevTime = 0;
        for (String log : logs) {
            String[] logParts = log.split(":");
            int curTime = Integer.parseInt(logParts[2]);
            if ("start".equals(logParts[1])) {
                if (!stack.isEmpty()) {
                    result[stack.peek()] += curTime - prevTime;
                }
                stack.push(Integer.parseInt(logParts[0]));
                prevTime = curTime;
            } else {
                result[stack.pop()] += curTime - prevTime + 1;
                prevTime = curTime + 1;
            }
        }
        return result;
    }
}

3. Exclusive Time of Functions LeetCode Solution JavaScript

var exclusiveTime = function(n, logs) {
    const sums = new Array(n).fill(0);
    const stack = [];
    let prevTime;
    logs.forEach(log => {
        const details = log.split(':');
        const id = parseInt(details[0]);
        const point = details[1];
        const time = parseInt(details[2]);
        if (point === 'start') {
            if (stack.length > 0) {
			    let prevFn = stack[stack.length - 1];
                sums[prevFn] += (time - prevTime);      
            }
            stack.push(id);
            prevTime = time;
        } else {
            const last = stack.pop();
            sums[last] += (time - prevTime + 1);
            prevTime = time + 1;
        }
    });
    return sums;
};

4. Exclusive Time of Functions LeetCode Solution Python

class Solution(object):
    def exclusiveTime(self, n, logs):
        helper = lambda log: (int(log[0]), log[1], int(log[2]))
        logs = [helper(log.split(':')) for log in logs]
        ans, s = [0] * n, []
        for (i, status, timestamp) in logs:
            if status == 'start':
                if s: ans[s[-1][0]] += timestamp - s[-1][1]
                s.append([i, timestamp])
            else:
                ans[i] += timestamp - s.pop()[1] + 1
                if s: s[-1][1] = timestamp+1
        return ans
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