Submission #100860

#	Time	Username	Problem	Language	Result	Execution time	Memory
100860		dalgerok	Drzava (COCI15_drzava)	C++17	160 / 160	208 ms	4016 KiB

drzava

#include<bits/stdc++.h>
#define ld long double
using namespace std;


const int N = 5e4 + 5, M = 31;



int n, k, x[N], y[N], z[N], a[N], p[N];
bool dp[N][M];

inline bool cmp(int xx, int yy){
    return x[xx] < x[yy] || (x[xx] == x[yy] && y[xx] < y[yy]);
}

inline long long dist(int i, int j){
    return 1LL * (x[i] - x[j]) * (x[i] - x[j]) + 1LL * (y[i] - y[j]) * (y[i] - y[j]);
}

int dsu_get(int v){
    return p[v] == v ? v : p[v] = dsu_get(p[v]);
}

inline void dsu_unite(int x, int y){
    x = dsu_get(x);
    y = dsu_get(y);
    if(x == y){
        return;
    }
    if(rand() & 1){
        swap(x, y);
    }
    p[y] = x;
    bool ndp[M];
    for(int i = 0; i < k; i++){
        ndp[i] = (dp[x][i] | dp[y][i]);
    }
    for(int i = 0; i < k; i++){
        for(int j = 0; j < k; j++){
            ndp[(i + j) % k] |= (dp[x][i] & dp[y][j]);
        }
    }
    for(int i = 0; i < k; i++){
        dp[x][i] |= ndp[i];
    }
}

inline bool check(long long val){
    for(int i = 1; i <= n; i++){
        p[a[i]] = a[i];
        memset(dp[a[i]], 0, sizeof(dp[a[i]]));
        dp[a[i]][z[a[i]]] = true;
    }
    set < pair < int, int > > q;
    q.insert(make_pair(y[a[1]], a[1]));
    int bound = (int)ceil(sqrt(val)) + 3;
    for(int i = 2, j = 1; i <= n; i++){
        while(x[a[i]] - x[a[j]] > bound){
            q.erase(make_pair(y[a[j]], a[j]));
            j += 1;
        }
        for(auto it = q.lower_bound(make_pair(y[a[i]] - bound, -1)); it != q.end(); it++){
            if(abs(y[a[i]] - it->first) > bound){
                break;
            }
            if(dist(a[i], it->second) <= val){
                dsu_unite(a[i], it->second);
            }
            if(dp[dsu_get(a[i])][0] == true){
                return true;
            }
        }
        if(dp[dsu_get(a[i])][0]){
            return true;
        }
        q.insert(make_pair(y[a[i]], a[i]));
    }
    return false;
}

int main(){
    ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    srand(time(nullptr));
    cin >> n >> k;
    for(int i = 1; i <= n; i++){
        cin >> x[i] >> y[i] >> z[i];
        z[i] %= k;
        a[i] = i;
    }
    sort(a + 1, a + n + 1, cmp);
    long long l = 0, r = 2e18;
    while(r - l > 1){
        long long mid = (r + l) >> 1;
        if(check(mid)){
            r = mid;
        }
        else{
            l = mid;
        }
    }
    if(check(l)){
        cout << fixed << setprecision(3) << sqrtl(l);
    }
    else{
        cout << fixed << setprecision(3) << sqrtl(r);
    }
}

• Subtask 1: 8 / 8
• Subtask 2: 8 / 8
• Subtask 3: 8 / 8
• Subtask 4: 8 / 8
• Subtask 5: 8 / 8
• Subtask 6: 8 / 8
• Subtask 7: 8 / 8
• Subtask 8: 8 / 8
• Subtask 9: 8 / 8
• Subtask 10: 8 / 8
• Subtask 11: 8 / 8
• Subtask 12: 8 / 8
• Subtask 13: 8 / 8
• Subtask 14: 8 / 8
• Subtask 15: 8 / 8
• Subtask 16: 8 / 8
• Subtask 17: 8 / 8
• Subtask 18: 8 / 8
• Subtask 19: 8 / 8
• Subtask 20: 8 / 8