☆打卡算法☆LeetCode 57、插入区间 算法解析

示例 1：
输入： intervals = [[1,3],[6,9]], newInterval = [2,5]
输出： [[1,5],[6,9]]

示例 2：
输入：intervals = [[1,2],[3,5],[6,7],[8,10],[12,16]], newInterval = [4,8]
输出：[[1,2],[3,10],[12,16]]
解释：这是因为新的区间 [4,8] 与 [3,5],[6,7],[8,10] 重叠。

public class Solution {
    public int[][] Insert(int[][] intervals, int[] newInterval) {
        if(newInterval.Length == 0) return intervals;
        int len = intervals.Length + 1;
        int[][] newIntervals = new int[len][];
        if(intervals.Length == 0) newIntervals[0] = newInterval;
        bool isFind = false;
        for (int i = intervals.Length - 1, j = len - 1; j >= 0; j--){
            if(i < 0){
                newIntervals[j] = newInterval;
                break;
            } 
            if (!isFind &amp;&amp; newInterval[0] >= intervals[i][0]){
                newIntervals[j] = newInterval;
                isFind = true;
            }
            else{
                newIntervals[j] = intervals[i];
                i--;
            }
        }
        List<int[]> lstRes = new List<int[]>();
        lstRes.Add(newIntervals[0]);
         //遍历合并，保存结果
        foreach(int[] currArr in newIntervals){
            int[] preArray = lstRes[lstRes.Count - 1];
            if(preArray[1] < currArr[0] || preArray[0] > currArr[1]){
                lstRes.Add(currArr);
            }
            else{
                int left = preArray[0] < currArr[0] ? preArray[0] : currArr[0];
                int right = preArray[1] > currArr[1] ? preArray[1] : currArr[1];
                lstRes[lstRes.Count - 1] = new int[2]{left, right};
            } 
        }
        return lstRes.ToArray();
    }
}