[LeetCode][JavaScript]Insert Interval

標籤：

https://leetcode.com/problems/insert-interval/

Insert Interval

Given a set of non-overlapping intervals, insert a new interval into the intervals (merge if necessary).

You may assume that the intervals were initially sorted according to their start times.

Example 1:
Given intervals [1,3],[6,9], insert and merge [2,5] in as [1,5],[6,9].

Example 2:
Given [1,2],[3,5],[6,7],[8,10],[12,16], insert and merge [4,9] in as [1,2],[3,10],[12,16].

This is because the new interval [4,9] overlaps with [3,5],[6,7],[8,10].

 

 

Javascript return的格式是錯的，好坑啊。

情況比較多，先全部列出來，大致上是五種，然後找找規律。

1. newInterval可以直接放進去，沒有重疊

console.log(JSON.stringify(insert([{start:3,end:4}], {start:5,end:6})) == JSON.stringify([[3,4],[5,6]]));console.log(JSON.stringify(insert([{start:5,end:6}], {start:3,end:4})) == JSON.stringify([[3,4],[5,6]]));console.log(JSON.stringify(insert([{start:3,end:4}, {start:8,end:9}], {start:6,end:7})) == JSON.stringify([[3,4],[6,7],[8,9]]));

2.newInterval與一個區間交叉

console.log(JSON.stringify(insert([{start:3,end:8}], {start:1,end:5})) == JSON.stringify([[1,8]]));console.log(JSON.stringify(insert([{start:3,end:8}], {start:5,end:10})) == JSON.stringify([[3,10]]));

3.newInterval 與左右2個區間交叉

console.log(JSON.stringify(insert([{start:3,end:5}, {start:9,end:11}], {start:4,end:10})) == JSON.stringify([[3,11]]));

4.newInterval “吃掉”了一個或多個區間

console.log(JSON.stringify(insert([{start:3,end:5}, {start:7,end:8}], {start:2,end:9})) == JSON.stringify([[2,9]]));

5.既有交叉，又“吃掉”了區間

console.log(JSON.stringify(insert([{start:3,end:5}, {start:6,end:7},{start:9,end:11}], {start:4,end:10})) == JSON.stringify([[3,11]]));console.log(JSON.stringify(insert([{start:1,end:3}, {start:5,end:6}], {start:2,end:7})) == JSON.stringify([[1,7]]));

解法：

/** * Definition for an interval. * function Interval(start, end) { *     this.start = start; *     this.end = end; * } *//** * @param {Interval[]} intervals * @param {Interval} newInterval * @return {Interval[]}  !!!!!!! wrong format */var insert = function(intervals, newInterval) {    var res = [];    var isInserted = false;    for(var i = 0; i < intervals.length; i++){        var curr = intervals[i];        if(curr.end < newInterval.start || isInserted){            res.push([curr.start, curr.end]);        }else if(newInterval.end < curr.start && !isInserted){            res.push([newInterval.start, newInterval.end]);            res.push([curr.start, curr.end]);            isInserted= true;        }else if(curr.start <= newInterval.start || newInterval.end <= curr.end){ //merge            newInterval.start = Math.min(curr.start, newInterval.start);            newInterval.end = Math.max(curr.end, newInterval.end);        }else{            // newInterval eat curr        }    }    if(!isInserted){        res.push([newInterval.start, newInterval.end]);    }    return res;};

 

 

 

 

[LeetCode][JavaScript]Insert Interval