[프로그래머스 3] 단속카메라 (C/C++) (★)

#include <string>
#include <vector>
#include <algorithm>
#include <iostream>
using namespace std;
 
int solution(vector<vector<int>> routes) 
{
    int answer = 0;
    
    sort(routes.begin(), routes.end());
    
    int s, e;
    int cnt = 0;
    for(int i = 0; i < routes.size();)
    {
        int s = routes[i][0];
        int e = routes[i][1];
        int cnt = 0;
                
        for(int j = i; j < routes.size(); j++)
        {
            if(s <= routes[j][0] && routes[j][0] <= e)
            {
                s = routes[j][0];
                e = min(e, routes[j][1]);
                cnt++;
            }
            else
            {
                break;
            }
        }
        
        i += cnt;
        answer++;
    }
 
    return answer;
}