合併對象，並返回冷凝範圍對象

Question

我解決這個問題：

寫功能mergeRanges（），它滿足時間 範圍的陣列，並返回冷凝範圍（1 = 30分鐘的陣列）

Input: 
[ 
    {startTime: 0, endTime: 1}, // meeting from 10:00 – 10:30 am (1 = 30 minutes) 
    {startTime: 3, endTime: 5}, // meeting from 12:00 – 1:30 pm 
    {startTime: 4, endTime: 8}, 
    {startTime: 10, endTime: 12}, 
    {startTime: 9, endTime: 10}, 
] 

Expected Output: 

[ 
    {startTime: 0, endTime: 1}, 
    {startTime: 3, endTime: 8}, 
    {startTime: 9, endTime: 12}, 
] 

我的解決辦法是/如下：

var arr = [ 
    {startTime: 0, endTime: 1}, 
    {startTime: 3, endTime: 5}, 
    {startTime: 4, endTime: 8}, 
    {startTime: 10, endTime: 12}, 
    {startTime: 9, endTime: 10}, 
]; 

function result(arr){ 
    var finalResult = {}; 

    var c = arr.sort(function(a,b){ //First Sort 
    return a.startTime - b.startTime; 
    }); 

    var d = c.reduce(function(a,b){ 

    //Logic 

    //check to see if start time lies between a[start] < b[startTime] < a[end] 

    // If the startTime lies between a[startTime] to b[endTime] -> Merge them. 

// if(a[startTime]< b[startTime] < b[endTime]){ //if start time lies between start and end. 
    // a[endTime] = b[endTime]; 
    // delete b; 
    // } 

    }); 

} 

result(arr); 

我無法理解如何使用reduce函數來交換邏輯。有人能夠啓發我嗎？

Answer 1

您可以使用reduce()和一個變量來存儲endTime。

var input = [ 
 
    {startTime: 0, endTime: 1}, 
 
    {startTime: 3, endTime: 5}, 
 
    {startTime: 4, endTime: 8}, 
 
    {startTime: 10, endTime: 12}, 
 
    {startTime: 9, endTime: 10}, 
 
] 
 

 
var c = 0; 
 
var result = input.reduce(function(r, e, i) { 
 
    //Check if c < startTime of current object in loop or if its first 
 
    //element and if it is add it to r 
 
    if (c < e.startTime || i == 0) { 
 
    r.push(e) 
 
    } else { 
 
    //if not check if endTime of current object is > c 
 
    //(so you don't have problem at last object where endTime is smaller then some previous endTime) and change it 
 
    //in r of last element that you added 
 
    if (e.endTime > c) r[r.length - 1].endTime = e.endTime 
 
    } 
 
    //Always set c to current endTime 
 
    c = e.endTime 
 
    return r 
 
}, []) 
 

 
console.log(result)