Submission #396739

#	Time	Username	Problem	Language	Result	Execution time	Memory
396739		AriaH	Circle selection (APIO18_circle_selection)	C++11	7 / 100	3108 ms	405520 KiB

circle_selection

/** vaziat sorati ghermeze **/

#pragma GCC optimize("O2")
#include <bits/stdc++.h>
using namespace std;

typedef long long                   ll;
typedef long double                 ld;
typedef pair<int,int>               pii;
typedef pair<ll,ll>                 pll;
#define all(x)                      (x).begin(),(x).end()
#define F                           first
#define S                           second
#define Mp                          make_pair
#define SZ(x)			    		(int)x.size()
#define fast_io                     ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define file_io                     freopen("in.txt" , "r+" , stdin) ; freopen("out.txt" , "w+" , stdout);

const int N = 1e6 + 10;
const ll mod = 1e9 + 7;
const ll mod2 = 998244353;
const ll inf = 8e18;
const int LOG = 22;

ll pw(ll a , ll b, ll M)  { return (!b ? 1 : (b & 1 ? (a * pw(a * a % M, b / 2, M)) % M : pw(a * a % M, b / 2, M))); }

int n, id[N], ord[N], mark[N], Ans[N];

ll X[N], Y[N], R[N];

vector < ll > cm, Vec;

set < pii > seg[N << 2];

bool cmp(int i, int j) { return R[i] > R[j]; }

inline int lwr(ll x) { return lower_bound(all(cm), x) - cm.begin(); }

bool cross(int i, int j)
{
	ll fir = (X[i] - X[j]) * (X[i] - X[j]) + (Y[i] - Y[j]) * (Y[i] - Y[j]);
	ll sec = R[i] * R[i] + R[j] * R[j] + 2 * R[i] * R[j];
	return sec >= fir;
}

void upd(pii x, int p, int v = 1, int tl = 0, int tr = SZ(cm))
{
	if(p > tr || p < tl) return;
	seg[v].insert(x);
	if(tl == tr) return;
	int mid = (tl + tr) >> 1;
	upd(x, p, v << 1, tl, mid);
	upd(x, p, v << 1 | 1, mid + 1, tr);
}

void get(int l, int r, int v = 1, int tl = 0, int tr = SZ(cm))
{
	if(l > tr || r < tl || l > r) return;
	if(l <= tl && tr <= r)
	{
		Vec.push_back(v);
		return;
	}
	int mid = (tl + tr) >> 1;
	get(l, r, v << 1, tl, mid);
	get(l, r, v << 1 | 1, mid + 1, tr);
}

int main()
{
	scanf("%d", &n);
	for(int i = 1; i <= n; i ++)
	{
		scanf("%lld%lld%lld", &X[i], &Y[i], &R[i]);
		cm.push_back(X[i]);
		ord[i] = i;
	}
	sort(ord + 1, ord + n + 1, cmp);
	/*for(int i = 1; i <= n; i ++)
	{
		printf("%d ", ord[i]);
	}
	printf("\n");*/
	sort(all(cm));
	cm.resize(unique(all(cm)) - cm.begin());
	for(int i = 1; i <= n; i ++)
	{
		id[i] = lwr(X[i]);
		upd(Mp(Y[i], i), id[i]);
	}
	for(int i = 1; i <= n; i ++)
	{
		int I = ord[i];
		if(Ans[I]) continue;
		ll l = lwr(X[I] - 2 * R[I]), r = lwr(X[I] + 2 * R[I]), d = Y[I] - 2 * R[I], up = Y[I] + 2 * R[I];
		Vec.clear();
		get(l, r);
		for(auto now : Vec)
		{
			pii last = Mp(d, -1);
			while(1)
			{
				auto it = seg[now].upper_bound(last);
				if(it == seg[now].end()) break;
				last = *it;
				if(Ans[it->S])
				{
					seg[now].erase(it);
					continue;
				}
				if(it->F <= up)
				{
					///printf("checking %d and %d\n", I, it->S);
					if(cross(it->S, I))
					{
						///printf("cross %d and %d\n", I, it->S);
						Ans[it->S] = I;
						seg[now].erase(it);
					}
					else
					{
						continue;
					}
				}
				else
				{
					break;
				}
			}
		}
	}
	for(int i = 1; i <= n; i ++)
	{
		printf("%d ", Ans[i]);
	}
    return 0;
}

/** test corner cases(n = 1?) watch for overflow or minus indices **/

Compilation message (stderr)

circle_selection.cpp: In function 'int main()':
circle_selection.cpp:71:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   71 |  scanf("%d", &n);
      |  ~~~~~^~~~~~~~~~
circle_selection.cpp:74:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   74 |   scanf("%lld%lld%lld", &X[i], &Y[i], &R[i]);
      |   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 7 / 7
• Subtask 2: 0 / 12
• Subtask 3: 0 / 15
• Subtask 4: 0 / 23
• Subtask 5: 0 / 30
• Subtask 6: 0 / 13