Submission #54465

#TimeUsernameProblemLanguageResultExecution timeMemory
54465SpaimaCarpatilorCircle selection (APIO18_circle_selection)C++17
100 / 100
1938 ms447580 KiB
#include<bits/stdc++.h>

using namespace std;

int N, x[300009], y[300009], r[300009], id[300009], oldOrd[300009], ord[300009], ans[300009];
pair < int, int > h[300009];

bool cmp (int i, int j)
{
    if (r[i] == r[j]) return (i < j);
    return (r[i] > r[j]);
}

unsigned int K = 1 << 31;
void doubleGrid ()
{
    memcpy (oldOrd, ord, sizeof (ord));
    int M = 0;
    for (int i=1; i<=N; i++)
    {
        int j = i;
        while (j < N && h[j + 1].first == h[j].first) j++;
        for (int k=0; k<2; k++)
            for (int l=i; l<=j; l++)
            {
                int r = l;
                while (r < j && h[r + 1].second == h[l].second) r ++;
                ///playing with [l, r]
                for (int p=0; p<2; p++)
                    for (int pos=l; pos<=r; pos++)
                        if (((x[oldOrd[pos]] % K) >= K / 2) == k &&
                            ((y[oldOrd[pos]] % K) >= K / 2) == p)
                                ord[++M] = oldOrd[pos];
                ///
                l = r;
            }
        i = j;
    }
    K /= 2;
    for (int i=1; i<=N; i++)
        h[i] = {x[ord[i]] / K, y[ord[i]] / K};
}

bool query (int i, int j)
{
    return (1LL * (x[i] - x[j]) * (x[i] - x[j]) + 1LL * (y[i] - y[j]) * (y[i] - y[j]) <= 1LL * (r[i] + r[j]) * (r[i] + r[j]));
}

void eliminate (int pos)
{
    int a = x[pos] / K, b = y[pos] / K;
    for (int i=max (a - 2, 0); i<=a + 2; i++)
    {
        pair < int, int > mi = {i, b - 2}, ma = {i, b + 2};
        int j = lower_bound (h + 1, h + N + 1, mi) - h, k;
        if (h[j].first != i || h[j].second > b + 2) continue;
        k = upper_bound (h + 1, h + N + 1, ma) - h - 1;
        for (int p=j; p<=k; p++)
            if (ans[ord[p]] == 0 && query (pos, ord[p]))
                ans[ord[p]] = pos;
    }
}

int main ()
{
//freopen ("input", "r", stdin);
//freopen ("output", "w", stdout);

scanf ("%d", &N);
for (int i=1; i<=N; i++)
    scanf ("%d %d %d", &x[i], &y[i], &r[i]),
    x[i] += 1e9, y[i] += 1e9,
    ord[i] = i, h[i] = {0, 0}, id[i] = i;
sort (id + 1, id + N + 1, cmp);
for (int i=1; i<=N; i++)
{
    while (K / 2 >= r[id[i]])
        doubleGrid ();
    if (ans[id[i]] == 0)
        eliminate (id[i]);
}
for (int i=1; i<=N; i++)
    printf ("%d%c", ans[i], " \n"[i == N]);
return 0;
}

Compilation message (stderr)

circle_selection.cpp: In function 'int main()':
circle_selection.cpp:77:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     while (K / 2 >= r[id[i]])
            ~~~~~~^~~~~~~~~~~
circle_selection.cpp:69:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
 scanf ("%d", &N);
 ~~~~~~^~~~~~~~~~
circle_selection.cpp:73:30: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf ("%d %d %d", &x[i], &y[i], &r[i]),
     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     x[i] += 1e9, y[i] += 1e9,
     ~~~~~~~~~~~~~~~~~~~~~~~~~~
     ord[i] = i, h[i] = {0, 0}, id[i] = i;
     ~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...