dev/democards/problems/problems/636.exclusive-time-of-functions.ipynb

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    "On a **single-threaded** CPU, we execute a program containing `n` functions.\n",
    "Each function has a unique ID between `0` and `n-1`.\n",
    "\n",
    "Function calls are **stored in a[call\n",
    "stack](https://en.wikipedia.org/wiki/Call_stack)**: when a function call\n",
    "starts, its ID is pushed onto the stack, and when a function call ends, its ID\n",
    "is popped off the stack. The function whose ID is at the top of the stack is\n",
    "**the current function being executed**. Each time a function starts or ends,\n",
    "we write a log with the ID, whether it started or ended, and the timestamp.\n",
    "\n",
    "You are given a list `logs`, where `logs[i]` represents the `ith` log message\n",
    "formatted as a string `\"{function_id}:{\"start\" | \"end\"}:{timestamp}\"`. For\n",
    "example, `\"0:start:3\"` means a function call with function ID `0` **started at\n",
    "the beginning** of timestamp `3`, and `\"1:end:2\"` means a function call with\n",
    "function ID `1` **ended at the end** of timestamp `2`. Note that a function\n",
    "can be called **multiple times, possibly recursively**.\n",
    "\n",
    "A function's **exclusive time** is the sum of execution times for all function\n",
    "calls in the program. For example, if a function is called twice, one call\n",
    "executing for `2` time units and another call executing for `1` time unit, the\n",
    "**exclusive time** is `2 + 1 = 3`.\n",
    "\n",
    "Return _the **exclusive time** of each function in an array, where the value\n",
    "at the _`ith` _index represents the exclusive time for the function with\n",
    "ID_`i`.\n",
    "\n",
    "\n",
    "\n",
    "**Example 1:**\n",
    "\n",
    "![](https://assets.leetcode.com/uploads/2019/04/05/diag1b.png)\n",
    "\n",
    "\n",
    "\n",
    "    Input: n = 2, logs = [\"0:start:0\",\"1:start:2\",\"1:end:5\",\"0:end:6\"]\n",
    "    Output: [3,4]\n",
    "    Explanation:\n",
    "    Function 0 starts at the beginning of time 0, then it executes 2 for units of time and reaches the end of time 1.\n",
    "    Function 1 starts at the beginning of time 2, executes for 4 units of time, and ends at the end of time 5.\n",
    "    Function 0 resumes execution at the beginning of time 6 and executes for 1 unit of time.\n",
    "    So function 0 spends 2 + 1 = 3 units of total time executing, and function 1 spends 4 units of total time executing.\n",
    "\n",
    "\n",
    "**Example 2:**\n",
    "\n",
    "\n",
    "\n",
    "    Input: n = 1, logs = [\"0:start:0\",\"0:start:2\",\"0:end:5\",\"0:start:6\",\"0:end:6\",\"0:end:7\"]\n",
    "    Output: [8]\n",
    "    Explanation:\n",
    "    Function 0 starts at the beginning of time 0, executes for 2 units of time, and recursively calls itself.\n",
    "    Function 0 (recursive call) starts at the beginning of time 2 and executes for 4 units of time.\n",
    "    Function 0 (initial call) resumes execution then immediately calls itself again.\n",
    "    Function 0 (2nd recursive call) starts at the beginning of time 6 and executes for 1 unit of time.\n",
    "    Function 0 (initial call) resumes execution at the beginning of time 7 and executes for 1 unit of time.\n",
    "    So function 0 spends 2 + 4 + 1 + 1 = 8 units of total time executing.\n",
    "\n",
    "\n",
    "**Example 3:**\n",
    "\n",
    "\n",
    "\n",
    "    Input: n = 2, logs = [\"0:start:0\",\"0:start:2\",\"0:end:5\",\"1:start:6\",\"1:end:6\",\"0:end:7\"]\n",
    "    Output: [7,1]\n",
    "    Explanation:\n",
    "    Function 0 starts at the beginning of time 0, executes for 2 units of time, and recursively calls itself.\n",
    "    Function 0 (recursive call) starts at the beginning of time 2 and executes for 4 units of time.\n",
    "    Function 0 (initial call) resumes execution then immediately calls function 1.\n",
    "    Function 1 starts at the beginning of time 6, executes 1 units of time, and ends at the end of time 6.\n",
    "    Function 0 resumes execution at the beginning of time 6 and executes for 2 units of time.\n",
    "    So function 0 spends 2 + 4 + 1 = 7 units of total time executing, and function 1 spends 1 unit of total time executing.\n",
    "\n",
    "\n",
    "**Example 4:**\n",
    "\n",
    "\n",
    "\n",
    "    Input: n = 2, logs = [\"0:start:0\",\"0:start:2\",\"0:end:5\",\"1:start:7\",\"1:end:7\",\"0:end:8\"]\n",
    "    Output: [8,1]\n",
    "\n",
    "\n",
    "**Example 5:**\n",
    "\n",
    "\n",
    "\n",
    "    Input: n = 1, logs = [\"0:start:0\",\"0:end:0\"]\n",
    "    Output: [1]\n",
    "\n",
    "\n",
    "\n",
    "\n",
    "**Constraints:**\n",
    "\n",
    "  * `1 <= n <= 100`\n",
    "  * `1 <= logs.length <= 500`\n",
    "  * `0 <= function_id < n`\n",
    "  * `0 <= timestamp <= 109`\n",
    "  * No two start events will happen at the same timestamp.\n",
    "  * No two end events will happen at the same timestamp.\n",
    "  * Each function has an `\"end\"` log for each `\"start\"` log."
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     "data": {
      "text/plain": "exclusive_time (generic function with 1 method)"
     },
     "metadata": {},
     "execution_count": 1
    }
   ],
   "cell_type": "code",
   "source": [
    "# @lc code=start\n",
    "using LeetCode\n",
    "\n",
    "function exclusive_time(n::Int, logs::Vector{T}) where {T<:AbstractString}\n",
    "    logs = [\n",
    "        (parse(Int, id) + 1, state, parse(Int, time)) for\n",
    "        (id, state, time) in split.(logs, ':')\n",
    "    ]\n",
    "    task, _, pretime = first(logs)\n",
    "    times, tasks = zeros(Int, n), [task]\n",
    "    for (id, state, curtime) in @views(logs[2:end])\n",
    "        interval, pretime = curtime - pretime, curtime\n",
    "        isempty(tasks) || (times[last(tasks)] += interval)\n",
    "        if state == \"start\" ## new task started\n",
    "            push!(tasks, id)\n",
    "        else ## task ended\n",
    "            times[pop!(tasks)] += 1 ## add end time\n",
    "            pretime += 1\n",
    "        end\n",
    "    end\n",
    "    return times\n",
    "end\n",
    "# @lc code=end"
   ],
   "metadata": {},
   "execution_count": 1
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    "---\n",
    "\n",
    "*This notebook was generated using [Literate.jl](https://github.com/fredrikekre/Literate.jl).*"
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