Submission #71324651

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Source Code Expand

#include <bits/stdc++.h>

using namespace std;

#ifdef LOCAL
#define debug(arg) cout << "[" << #arg << "]: " << arg << endl
#else
#define debug(arg) 42
#endif

using llu = unsigned long long;
using ll = long long;

#define vec vector
#define pb push_back
#define all(n) begin(n), end(n)

void solv() {
	int n; cin >> n;
	vec<pair<int, int>> xr(n);
	for (auto &[x, r] : xr) cin >> x >> r;
	vec<int> vals;
	for (auto &[x, r] : xr) vals.pb(x - r), vals.pb(x + r);
	sort(all(vals)), vals.erase(unique(all(vals)), vals.end());
	n = vals.size();
	vec<vec<int>> adj(n);
	for (auto &[x, r] : xr) {
		int u = lower_bound(all(vals), x - r) - vals.begin();
		int v = lower_bound(all(vals), x + r) - vals.begin();
		adj[u].pb(v);
		adj[v].pb(u);
	}
	vec<bool> vis(n);
	auto dfs = [&](auto &&dfs, int u, int p = -1) -> bool {
		if (vis[u]) return true;
		vis[u] = true;
		bool res = false;
		for (auto &v : adj[u]) if (v != p) res |= dfs(dfs, v, u);
		return res;
	};
	int ans = 0;
	debug(n);
	for (int i = 0; i < n; ++i) ans += dfs(dfs, i);
	cout << ans << '\n';
}

signed main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	int t = 1;
	//cin >> t;
	while (t--) solv();
	return 0;
}

Submission Info

Judge Result