leetCode 57.Insert Interval (插入區間) 解題思路和方法
阿新 • • 發佈:2017-07-29
use example ava article urn win time 例如 ont
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].
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].
思路:插入合並就可以,相比於上一題。這題還要簡單一些。
詳細代碼例如以下:
/** * Definition for an interval. * public class Interval { * int start; * int end; * Interval() { start = 0; end = 0; } * Interval(int s, int e) { start = s; end = e; } * } */ public class Solution { public List<Interval> insert(List<Interval> intervals, Interval newInterval) { List<Interval> list = new ArrayList<Interval>(); //邊界情況 if(intervals.size() == 0){ list.add(newInterval); return list; } //循環推斷 for(int i = 0; i < intervals.size();i++){ //假設新的區間結束值小於開始值。則直接插入前面。後面依次插入就可以 if(newInterval.end < intervals.get(i).start){ list.add(newInterval); for(int j = i; j < intervals.size(); j++){ list.add(intervals.get(j)); } break; } //新的區間開始點大於結束點。則當前點直接加入結果集 else if(newInterval.start > intervals.get(i).end){ list.add(intervals.get(i)); } //須要合並的情況 else{ //合並區間 newInterval.start = Math.min(newInterval.start,intervals.get(i).start); newInterval.end = Math.max(newInterval.end,intervals.get(i).end); } if(i == intervals.size() - 1){//假設是最後一個數據。也加入結果集中 list.add(newInterval); } } return list; } }
leetCode 57.Insert Interval (插入區間) 解題思路和方法