Submission #1104725

#	Time	Username	Problem	Language	Result	Execution time	Memory
1104725		tuannm	Park (BOI16_park)	C++17	100 / 100	472 ms	70464 KiB

park

#include<bits/stdc++.h>
#define ii pair<int, int>
#define ll pair<long long, long long>
#define fi first
#define se second
#define pb push_back
using namespace std;
const int mod[2] = {1000000007, 998244353};
const int N = 2e3 + 5;
const string NAME = "escaping";
int n, m, w, h;
int p[N], ans[100001];

vector<tuple<int, int, int>> queries;
vector<tuple<long double, int, int>> edges;

int find_set(int u){
    if(u == p[u])
        return u;

    return p[u] = find_set(p[u]);
}

void join_set(int u, int v){
    u = find_set(u);
    v = find_set(v);

    if(u == v)
        return;

    p[v] = u;
}

struct circ{
    long double x, y, r;

    circ(long double _x = 0, long double _y = 0, long double _r = 0) : x(_x), y(_y), r(_r) {}
} a[N];

long double dis(int i, int j){
    long double gg = 1.0 * (a[i].x - a[j].x) * (a[i].x - a[j].x) + 1.0 * (a[i].y - a[j].y) * (a[i].y - a[j].y);
    gg = sqrtl(gg);

    gg -= 1.0 * (a[i].r + a[j].r);

    return gg;
}

bool ok(int i, int j){
    return find_set(i) != find_set(j);
}

bool check(int i, int j){
    if(i == j)
        return true;

    if(i > j)
        swap(i, j);

    if(i == 1 && j == 2)
        return (ok(n + 1, n + 2) && ok(n + 1, n + 3) && ok(n + 1, n + 4));

    if(i == 1 && j == 3)
        return (ok(n + 1, n + 3) && ok(n + 1, n + 4) && ok(n + 2, n + 3) && ok(n + 2, n + 4));

    if(i == 1 && j == 4)
        return (ok(n + 1, n + 4) && ok(n + 2, n + 4) && ok(n + 3, n + 4));

    if(i == 2 && j == 3)
        return (ok(n + 1, n + 2) && ok(n + 2, n + 3) && ok(n + 2, n + 4));

    if(i == 2 && j == 4)
        return (ok(n + 1, n + 2) && ok(n + 1, n + 3) && ok(n + 2, n + 4) && ok(n + 3, n + 4));

    return (ok(n + 1, n + 3) && ok(n + 2, n + 3) && ok(n + 3, n + 4));
}

void inp(){
    cin >> n >> m >> w >> h;

    for(int i = 1; i <= n; ++i){
        int x, y, r;
        cin >> x >> y >> r;

        a[i] = circ(x, y, r);
    }

    for(int i = 1; i <= m; ++i){
        int r, e;
        cin >> r >> e;

        queries.pb({r, e, i});
    }
}

void solve(){
    for(int i = 1; i <= n; ++i)
        for(int j = i + 1; j <= n; ++j){
            long double W = dis(i, j);

            edges.pb({W, i, j});
        }

    for(int i = 1; i <= n; ++i){
        long double W = (a[i].y <= a[i].r ? 0 : a[i].y - a[i].r);

        edges.pb({W, i, n + 1});
    }

    for(int i = 1; i <= n; ++i){
        long double W = (w - a[i].x <= a[i].r ? 0 : w - a[i].x - a[i].r);

        edges.pb({W, i, n + 2});
    }

    for(int i = 1; i <= n; ++i){
        long double W = (h - a[i].y <= a[i].r ? 0 : h - a[i].y - a[i].r);

        edges.pb({W, i, n + 3});
    }

    for(int i = 1; i <= n; ++i){
        long double W = (a[i].x <= a[i].r ? 0 : a[i].x - a[i].r);

        edges.pb({W, i, n + 4});
    }

    sort(edges.begin(), edges.end());
    sort(queries.begin(), queries.end());

    for(int i = 1; i <= n + 4; ++i)
        p[i] = i;

    int ptr = 0;
    for(auto [r, e, i] : queries){
        while(ptr < edges.size()){
            auto [W, u, v] = edges[ptr];
            if(W >= 2 * r)
                break;

            join_set(u, v);
            ++ptr;
        }

        for(int j = 1; j <= 4; ++j)
            if(check(e, j))
                ans[i] |= (1 << j);
    }

    for(int i = 1; i <= m; ++i){
        for(int j = 1; j <= 4; ++j)
            if((ans[i] >> j) & 1)
                cout << j;
        cout << "\n";
    }
}

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    if(fopen((NAME + ".inp").c_str(), "r")){
        freopen((NAME + ".inp").c_str(), "r", stdin);
        freopen((NAME + ".out").c_str(), "w", stdout);
    }

    inp();
    solve();
}

Compilation message (stderr)

park.cpp: In function 'void solve()':
park.cpp:136:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::tuple<long double, int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  136 |         while(ptr < edges.size()){
      |               ~~~~^~~~~~~~~~~~~~
park.cpp: In function 'int main()':
park.cpp:164:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  164 |         freopen((NAME + ".inp").c_str(), "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
park.cpp:165:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  165 |         freopen((NAME + ".out").c_str(), "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 27 / 27
• Subtask 2: 31 / 31
• Subtask 3: 42 / 42