Submission #49140

#	Time	Username	Problem	Language	Result	Execution time	Memory
49140		BThero	Circle selection (APIO18_circle_selection)	C++17	87 / 100	3038 ms	41480 KiB

circle_selection

// Why am I so stupid? :c
#include <bits/stdc++.h>

#define pb push_back
#define mp make_pair

#define all(x) (x).begin(), (x).end()

#define fi first
#define se second

typedef long long ll;

using namespace std;

struct circle {
    int x, y, r, id;

    circle() {
        x = y = r = id = 0;
    }
} arr[300005];

map < ll, vector <int> > mm;

int ans[300005];

int u[300005];

int n, cur;

int block;

bool inter(circle a, circle b) {
    ll dist = (a.x - b.x) * 1ll * (a.x - b.x) + (a.y - b.y) * 1ll * (a.y - b.y);
    return dist <= (a.r + b.r) * 1ll * (a.r + b.r);
}

bool cmp(circle a, circle b) {
    if (a.r == b.r) {
        return a.id < b.id;
    }

    return a.r > b.r;
}

ll f(int x, int y) {
    return x * (ll)2e9 + y;
}

void divIntoBlocks(int st) {
    mm.clear();

    for (int i = st; i <= n; ++i) {
        if (ans[arr[i].id] == arr[i].id) {
            mm[f(arr[i].x / block, arr[i].y / block)].pb(i);
        }
    }
}

void solve() {
    scanf("%d", &n);

    for (int i = 1; i <= n; ++i) {
        scanf("%d %d %d", &arr[i].x, &arr[i].y, &arr[i].r);
        arr[i].id = i;
    }

    sort(arr + 1, arr + n + 1, cmp);

    for (int i = 1; i <= n; ++i) {
        ans[i] = i;
    }

    vector <int> vv;

    for (int i = 1; i <= n; ++i) {
        if (ans[arr[i].id] != arr[i].id) {
            continue;
        }

        if (block == 0 || arr[i].r * 10ll <= block) {
            block = arr[i].r;
            divIntoBlocks(i + 1);
        }

        int cx = arr[i].x / block;
        int cy = arr[i].y / block;

        for (int x = cx - 2; x <= cx + 2; ++x) {
            for (int y = cy - 2; y <= cy + 2; ++y) {
                ll cur = f(x, y);
                auto P = mm.find(cur);
                vv.clear();

                if (P != mm.end()) {
                    for (int it : P -> se) {
                        if (inter(arr[i], arr[it])) {
                            ans[arr[it].id] = arr[i].id;
                        }
                        else {
                            vv.pb(it);
                        }
                    }

                    P -> se = vv;
                }
            }
        }

        /*

        for (int j = i + 1; j <= n; ++j) {
            if (ans[arr[j].id] == arr[j].id) {
                if (inter(arr[i], arr[j])) {
                    ans[arr[j].id] = arr[i].id;
                }
            }
        }

        */
    }

    for (int i = 1; i <= n; ++i) {
        printf("%d ", ans[i]);
    }
}

int main() {
#ifdef BThero
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#endif // BThero

    int tt = 1;

    while (tt--) {
        solve();
    }

    return 0;
}

Compilation message (stderr)

circle_selection.cpp: In function 'void solve()':
circle_selection.cpp:62:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &n);
     ~~~~~^~~~~~~~~~
circle_selection.cpp:65:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d %d %d", &arr[i].x, &arr[i].y, &arr[i].r);
         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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