Submission #430935

#	Time	Username	Problem	Language	Result	Execution time	Memory
430935		Hideo	IOI Fever (JOI21_fever)	C++17	25 / 100	228 ms	1848 KiB

fever

#include <bits/stdc++.h>
using namespace std;

#define all(s) s.begin(), s.end()
#define ll long long
#define fr first
#define sc second
#define pb push_back
#define mk make_pair
#define pi pair < int, int >

const int N = 3007;
const int INF = 1e9 + 7;

pi d[4] = {{1, 0}, {-1, 0}, {0, -1}, {0, 1}};

int x[N], y[N];
int us[N];
int n, ans;

int check (int v, int u, int k, double t){
    if (abs(x[v] - x[u]) != abs(y[v] - y[u])){
        if (x[v] == x[u]){
            if (t > abs(y[v] - y[u]) / 2.0)
                return -10;
            if (k == 2 && y[v] > y[u])
                return -3;
            if (k == 3 && y[v] < y[u])
                return -2;
        }
        else if (y[v] == y[u]){
            if (t > abs(x[v] - x[u]) / 2.0)
                return -10;
            if (k == 1 && x[v] > x[u])
                return -4;
            if (k == 0 && x[v] < x[u])
                return -1;
        }
        return -10;
    }
    if (t > abs(x[v] - x[u]))
        return -10;
    if (k == 0){
        if (x[u] < x[v])
            return -10;
        if (y[u] > y[v])
            return 2;
        else
            return 3;
    }
    if (k == 1){
        if (x[u] > x[v])
            return -10;
        if (y[u] > y[v])
            return 2;
        else
            return 3;
    }
    if (k == 2){
        if (y[u] > y[v])
            return -10;
        if (x[u] > x[v])
            return 1;
        else
            return 0;
    }
    if (k == 3){
        if (y[u] < y[v])
            return -10;
        if (x[u] > x[v])
            return 1;
        else
            return 0;
    }
}

int solve (int ks){
    int r = 0;
    priority_queue < pair < double, pi > > qr;
    qr.push({0, {ks, 1}});
    while (!qr.empty()){
        double t = -qr.top().fr;
        int k = qr.top().sc.fr, v = qr.top().sc.sc;
        qr.pop();
        if (us[v])
            continue;
        r++;
        us[v] = 1;
        for (int i = 2; i <= n; i++){
            if (us[i])
                continue;
            int nk = check(v, i, k, t);
            if (nk != -10){
                if (nk < 0){
                    if (nk == -4)
                        nk = 0;
                    qr.push({-(abs(x[v] - x[i]) / 2.0), {-nk, i}});
                }
                else
                    qr.push({-abs(x[v] - x[i]), {nk, i}});
            }
        }
    }
    return r;
}

main (){
    cin >> n;
    for (int i = 1; i <= n; i++){
        cin >> x[i] >> y[i];
    }
    ans = max(ans, solve(0));
    memset(us, 0, sizeof(us));
    ans = max(ans, solve(1));
    memset(us, 0, sizeof(us));
    ans = max(ans, solve(2));
    memset(us, 0, sizeof(us));
    ans = max(ans, solve(3));
    cout << ans;
}

Compilation message (stderr)

fever.cpp:107:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
  107 | main (){
      | ^~~~
fever.cpp: In function 'int check(int, int, int, double)':
fever.cpp:75:1: warning: control reaches end of non-void function [-Wreturn-type]
   75 | }
      | ^

• Subtask 1: 5 / 5
• Subtask 2: 8 / 8
• Subtask 3: 6 / 6
• Subtask 4: 6 / 6
• Subtask 5: 0 / 12
• Subtask 6: 0 / 32
• Subtask 7: 0 / 31