Codeforces Round #513 D. Social Circles(思维)

#include <bits/stdc++.h>
#define maxn 100005
#define ll long long
using namespace std;
int r[maxn],l[maxn];
int n;

int main()
{
  scanf("%d",&n);
  for(int i=0;i<n;i++)scanf("%d%d",&l[i],&r[i]);
  sort(l, l + n);
  sort(r, r + n);
  ll ans = 0;
  for(int i=n-1;i>=0;i--){
    ans += max(l[i], r[i]);
  }
  cout << ans + n << endl;
  return 0;
}