백준 16936번 C++ 풀이

벡터로 담아 정렬한 뒤에 하나씩 갱신합니다.

#include <iostream>
#include <algorithm>
#include <queue>
#include <climits>
using namespace std;

int buffer[1001];
bool isVisited[1001];
int main(){
    cin.tie(NULL);
    ios::sync_with_stdio(false);

    int n;
    cin >> n;
    vector<pair<int, int>> v;
    for (auto i=0; i<n; i++){
        int x,y;
        cin >> x >> y;

        v.push_back(make_pair(min(x,y),max(x,y)));
    }
    sort(v.begin(), v.end());
    long long totalLength = 0;
//    bool shouldThinkPrevious = false;
    for (auto i=1; i<v.size(); i++){
//        if( shouldThinkPrevious == false){
//            shouldThinkPrevious = true;
//            continue;
//        }
        if ( v[i-1].second < v[i].first){ //청산이 필요함
            totalLength += v[i-1].second - v[i-1].first;
        }else {
            v[i].first = min(v[i].first, v[i-1].first);
            v[i].second = max(v[i].second,  v[i-1].second);
        }
    }
    totalLength += v[v.size()-1].second - v[v.size()-1].first;

    cout << totalLength;
    return 0;

}