단속 카메라

#include <string>
#include <vector>
#include <algorithm>
#include <iostream>

using namespace std;

int solution(vector<vector<int>> routes) {
	int answer = 1;

	sort(routes.begin(), routes.end());

	int range = routes[0][1];
	for (int i = 1; i < routes.size(); i++) {
		if (range >= routes[i][1])
			range = routes[i][1];
		if(range < routes[i][0]){
			answer++;
			range = routes[i][1];
		}
	}
	return answer;
}