USACO Platinum 2019 Open - Valleys

No need to measure "curvature" ... Just maintain # of holes in each region with two DSUs.

Copy
#include <bits/stdc++.h>
using namespace std;

using ll = long long;
using ld = long double;
using db = double;
using str = string;  // yay python!

using pi = pair<int, int>;
using pl = pair<ll, ll>;