leetcode-1/src/insertInterval/insertInterval.cpp at master · daction/leetcode-1 · GitHub

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

// Author : Hao Chen

// Date : 2014-08-26

/**********************************************************************************

* 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].

**********************************************************************************/

#include <iostream>

#include <vector>

#include <algorithm>

using namespace std;

struct Interval {

int start;

int end;

Interval() : start(0), end(0) {}

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

};

//Two factors sorting [start:end]

bool compare(const Interval& lhs, const Interval& rhs){

return (lhs.start==rhs.start) ? lhs.end < rhs.end : lhs.start < rhs.start;

}

vector<Interval> merge(vector<Interval> &intervals) {

vector<Interval> result;

if (intervals.size() <= 0) return result;

//sort the inervals. Note: using the customized comparing function.

sort(intervals.begin(), intervals.end(), compare);

for(int i=0; i<intervals.size(); i++) {

int size = result.size();

// if the current intervals[i] is overlapped with previous interval.

// merge them together

if( size>0 && result[size-1].end >= intervals[i].start) {

result[size-1].end = max(result[size-1].end, intervals[i].end);

}else{

result.push_back(intervals[i]);

}

return result;

}

//just reuse the solution of "Merge Intervals", quite straight forward

vector<Interval> insert(vector<Interval> &intervals, Interval newInterval) {

intervals.push_back(newInterval);

return merge(intervals);

}

int main(int argc, char**argv)

{

Interval i1(1,2);

Interval i2(3,5);

Interval i3(6,7);

Interval i4(8,10);

Interval i5(12,16);

vector<Interval> intervals;

intervals.push_back(i1);

intervals.push_back(i2);

intervals.push_back(i3);

intervals.push_back(i4);

intervals.push_back(i5);

Interval n(4,9);

vector<Interval> r = insert(intervals, n);

for(int i=0; i<r.size(); i++){

cout << "[ " << r[i].start << ", " << r[i].end << " ] ";

}

cout <<endl;

return 0;

}

leetcode-1/src/insertInterval/insertInterval.cpp at master · daction/leetcode-1 · GitHub

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