Submission #915928

#	Time	Username	Problem	Language	Result	Execution time	Memory
915928		biank	Soccer Stadium (IOI23_soccer)	C++17	0 / 100	2 ms	4952 KiB

soccer

#include <bits/stdc++.h>
using namespace std;
#define ALL(x) x.begin(),x.end()
#define SIZE(x) (int)x.size()
#define forsn(i,s,n) for(int i=int(s);i<int(n);i++)
#define forn(i,n) for(int i=0;i<int(n);i++)
#define dforsn(i,s,n) for(int i=int(n)-1;i>=int(s);i--)
#define dforn(i,n) for(int i=int(n)-1;i>=0;i--)
#define fst first
#define snd second
typedef pair<int,int> ii;
const int MAXN = 500;
int f[MAXN][MAXN];
int dp[MAXN][MAXN];
ii ran[MAXN][MAXN];
int L[MAXN][MAXN], R[MAXN][MAXN];

int n;

pair<int,ii> solve(int l, int r, int p) {
    if(l>r) return {0LL,{-1,n}};
    if(dp[l][r]!=-1) return {dp[l][r],ran[l][r]};
    auto calculate = [&](pair<int,ii> prev, int i) {
        auto [val,range] = prev;
        int mini = max(range.fst, L[i][p]), maxi = min(range.snd, R[i][p]);
        return (pair<int,ii>){val+max(maxi-mini-1,0),{mini,maxi}};
    };
    pair<int,ii> res = max(calculate(solve(l+1,r,p),l),
                           calculate(solve(l,r-1,p),r));
    dp[l][r]=res.fst, ran[l][r]=res.snd;
    return res;
}

int only_check(vector<vector<int>> f) {
    vector<int> l(n,n), r(n,-1);
    forn(i,n) forn(j,n) {
        if(f[i][j]==0) {
            l[i]=min(l[i],j);
            r[i]=max(r[i],j);
        }
    }
    forn(i,n) forsn(j,l[i],r[i]+1) {
        if(f[i][j]==1) return -1;
    }
    forn(i,n) forn(j,n) {
        if(l[i]>l[j] && r[i]>r[j]) return -1;
    }
    
    vector<int> c(n);
    forn(i,n) c[i]=max(r[i]-l[i]+1,0);
    int maxi = int(max_element(ALL(c)) - c.begin());
    forsn(i,maxi,n-1) {
        if(c[i]<c[i+1]) return -1;
    }
    forn(i,maxi) {
        if(c[i]>c[i+1]) return -1;
    }
    int count=0;
    forn(i,n) forn(j,n) {
        count += f[i][j]==0;
    }
    return count;
}

int subtask1(vector<vector<int>> f) {
    ii pos={-1,-1};
    forn(i,n) forn(j,n) {
        if(f[i][j]==1) pos={i,j};
    }
    auto calculate = [](int i, int j) {
        return n*n-(i+1)*(j+1);
    };
    auto [i,j] = pos;
    return max({calculate(i,j),calculate(n-i-1,j),calculate(i,n-j-1),calculate(n-i-1,n-j-i)});
}

int biggest_stadium(int N, vector<vector<int>> F) {
    n=N;
    int count=0;
    forn(i,n) forn(j,n) {
        count += F[i][j]==1;
    }
    if(count<=1) return subtask1(F);
    if(n>500) return only_check(F);
    forn(i,n) forn(j,n) {
        f[i][j]=F[i][j];
    }
    forn(i,n) {
        int k=-1;
        forn(j,n) {
            if(f[i][j]==1) k=j;
            L[i][j]=k;
        }
    }
    forn(i,n) {
        int k=n;
        dforn(j,n) {
            if(f[i][j]==1) k=j;
            R[i][j]=k;
        }
    }
    int ans=0;
    forn(i,n) {
        memset(dp,-1,sizeof dp);
        ans=max(ans,solve(0,n-1,i).fst);
    }
    return ans;
}

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