[LeetCode]57.Insert Interval

题目

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

跟[LeetCode]56.Merge Intervals思路差不多。

代码

/*---------------------------------------------------------
*   日期：2015-04-22
*   作者：SJF0115
*   题目: 57.Insert Interval
*   网址：https://leetcode.com/problems/insert-interval/
*   结果：AC
*   来源：LeetCode
*   博客：
------------------------------------------------------------*/
#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;

struct Interval {
    int start;
    int end;
    Interval() : start(0), end(0) {}
    Interval(int s, int e) : start(s), end(e) {}
};

class Solution {
public:
    vector<Interval> insert(vector<Interval> &intervals, Interval newInterval) {
        vector<Interval> result;
        result.push_back(newInterval);
        int size = intervals.size();
        if(size <= 0){
            return result;
        }//if
        // 插入
        for(int i = 0;i < size;++i){
            Interval one = result.back();
            Interval two = intervals[i];
            // [1,3] [5,6]
            // 插入倒数第二位
            if(two.end < one.start){
                Interval tmp = result.back();
                result.pop_back();
                result.push_back(two);
                result.push_back(tmp);
            }//if
            // 插入最后一位
            else if(two.start > one.end){
                result.push_back(two);
            }//else
            // 需合并
            else{
                int start = min(one.start,two.start);
                int end = max(one.end,two.end);
                Interval tmp(start,end);
                result.pop_back();
                result.push_back(tmp);
            }//else
        }//for
        return result;
    }
};

int main(){
    Solution solution;
    Interval in1(1,2);
    Interval in2(3,5);
    Interval in3(6,7);
    Interval in4(8,10);
    Interval in5(12,16);

    vector<Interval> vec;
    vec.push_back(in1);
    vec.push_back(in2);
    vec.push_back(in3);
    vec.push_back(in4);
    vec.push_back(in5);

    Interval newInterval(4,9);
    // 合并
    vector<Interval> v = solution.insert(vec,newInterval);
    // 输出
    for(int i = 0;i < v.size();i++){
        Interval in = v[i];
        cout<<"["<<in.start<<","<<in.end<<"]"<<endl;
    }//for
    return 0;
}

运行时间