Submission #1072587

#	Time	Username	Problem	Language	Result	Execution time	Memory
1072587		HorizonWest	Soccer Stadium (IOI23_soccer)	C++17	8 / 100	1 ms	600 KiB

soccer

#include <iostream>
#include <complex>
#include <iomanip>
#include <vector>
#include <algorithm>
#include <functional>
#include <bitset>
#include <queue>
#include <map>
#include <stack>
#include <cmath>
#include <cstdint>
#include <cassert>
using namespace std;

const int Max = 3001, Inf = 1e9, TLE = 3e6;

#define ll unsigned long long

int lg[Max], cnt; 

struct SPTMIN
{
    vector <vector <int>> spt; 

    int query(int i, int j){
        int x = lg[j-i+1];
        return min(spt[i][x], spt[j - (1LL << x) + 1][x]);
    }

    SPTMIN(vector <int> v)
    {
        int n = v.size();
        spt.assign(n + 1, vector <int> (lg[n] + 1, Inf));

        for(int j = 0; j < lg[n]+1; j++)
        {
            for(int i = 0; i < n; i++){
                if(j == 0){
                    spt[i][j] = v[i];
                    continue;
                }
                spt[i][j] = spt[i][j-1];
                if(i + (1LL << (j-1)) < n) spt[i][j] = min(spt[i][j-1], spt[i + (1LL << (j-1))][j-1]);
            }
        }
    }
};

struct SPTMAX
{
    vector <vector <int>> spt; 

    int query(int i, int j){
        int x = lg[j-i+1];
        return max(spt[i][x], spt[j - (1LL << x) + 1][x]);
    }

    SPTMAX(vector <int> v)
    {
        int n = v.size();
        spt.assign(n + 1, vector <int> (lg[n] + 1, 0));

        for(int j = 0; j < lg[n]+1; j++)
        {
            for(int i = 0; i < n; i++){
                if(j == 0){
                    spt[i][j] = v[i];
                    continue;
                }
                spt[i][j] = spt[i][j-1];
                if(i + (1LL << (j-1)) < n) spt[i][j] = max(spt[i][j-1], spt[i + (1LL << (j-1))][j-1]);
            }
        }
    }
};

int rnd()
{
  	int ans = rand(); 
  	return (ans ^ (ans << 5) ^ (ans << 15));
}

int biggest_stadium(int n, std::vector<std::vector<int>> f)
{
    vector <vector<int>> A(n, vector <int> (n, 0)),
        B(n, vector <int> (n, 0)),
        C(n, vector <int> (n, 0)),
        D(n, vector <int> (n, 0)); 

    vector <SPTMIN> sp1;
    vector <SPTMAX> sp2;

    cnt = 0;

    for(int i = 1; i <= n; i++){
        lg[i] = log2(i);
    }

    for(int i = 0; i < n; i++)
    {
        int last = -1; 
        for(int j = 0; j < n; j++){
            if(f[i][j] == 1) last = j; 
            A[i][j] = last;
        }   

        last = n;
        for(int j = n-1; j >= 0; j--){
            if(f[i][j] == 1) last = j; 
            B[i][j] = last;
        }     
    }

    for(int i = 0; i < n; i++)
    {
        int last = -1; 
        for(int j = 0; j < n; j++){
            if(f[j][i] == 1) last = j; 
            C[j][i] = last+1;
        }   

        last = n;
        for(int j = n-1; j >= 0; j--){
            if(f[j][i] == 1) last = j; 
            D[j][i] = last-1;
        }     
    }

    for(int i = 0; i < n; i++)
    {
        sp1.push_back(SPTMIN(D[i]));
        sp2.push_back(SPTMAX(C[i]));
    }
    
    //return 0;

    //vector <vector<vector<int>>> dp1(n + 1, vector <vector<int>> 
    //    (n + 1, vector <int> (n + 1, -1)));

    //vector <vector<vector<int>>> dp2(n + 1, vector <vector<int>> 
    //    (n + 1, vector <int> (n + 1, -1)));

    unordered_map <ll, int> dp; 

    auto F = [&](auto F, int i, int j, int a, int b, int c, int d) -> int 
    {   cnt++;

        long long x = ((ll) b) + (((ll) c) << 11LL) + (((ll) d) << 22LL) + (((ll) j) << 33LL) 
                               + (((ll) i) << 44LL) + (((ll) a) << 55LL);
        
        if(dp[x] != 0) return dp[x];
        dp[x] = (b - a + 1); 
        if(i != j) dp[x] += (d - c + 1);

        int mx = 0;

        if(i != 0)
        {
            for(int k = a; k <= b; k++) if(f[i-1][k] == 0)
            {
                int l1 = max(A[i-1][k]+1, a), r1 = min(B[i-1][k]-1, b);
                int l2 = max(c, l1), r2 =  min(d, r1);

                int ni = sp2[i].query(l1, r1), d = abs(ni - i) - 1, t = (r1 - l1 + 1);

                mx = max(mx, F(F, ni, j, l1, r1, l2, r2) - (r2 - l2 + 1) + d * t);

                k = r1;
            }
        }

        if(j != n-1)
        {
            for(int k = c; k <= d; k++) if(f[j+1][k] == 0)
            {
                int l2 = max(A[j+1][k]+1, c), r2 = min(B[j+1][k]-1, d);
                int l1 = max(a, l2), r1 =  min(b, r2);

                int nj = sp1[j].query(l2, r2), d = abs(nj - j) - 1, t = (r2 - l2 + 1);

                mx = max(mx, F(F, i, nj, l1, r1, l2, r2) - (r1 - l1 + 1) + d * t);

                k = r2;
            }
        }

        return dp[x] = (dp[x] + mx);
    };      
    
    int ans = 0; 
  	
  	srand(time(NULL));
  	vector <pair<int, int>> fx; 
  
    for(int i = 0; i < n; i++)
    {
        for(int j = 0; j < n; j++)
        {
            fx.push_back({ i, j });
        }
    }
  	
  	int mod = (int) fx.size(); 
 	for(int i = 0; i < (int) fx.size(); i++){
      int x = rnd() % mod;
      swap(fx[i], fx[x]);
    }
  
  	for(auto& u : fx)
    {
      int i = u.first, j = u.second; 
      
      if(f[i][j] == 1) continue; 
      
      int l = A[i][j]+1, r = B[i][j]-1;

      ans = max(ans, F(F, i, i, l, r, l, r));

      if(n > 500 && cnt > TLE) {
        return ans;
      }
    }

    return ans;
}

• Subtask 0: 0 / 0
• Subtask 1: 0 / 6
• Subtask 2: 8 / 8
• Subtask 3: 0 / 22
• Subtask 4: 0 / 18
• Subtask 5: 0 / 16
• Subtask 6: 0 / 30