제출 #335810

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
335810		talant117408	Bomb (IZhO17_bomb)	C++17	90 / 100	646 ms	129200 KiB

bomb

/*
    Code written by Talant I.D.
*/
#include <bits/stdc++.h>
//#include <ext/pb_ds/assoc_container.hpp>

//using namespace __gnu_pbds;
using namespace std;

//typedef tree <int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> indexed_set;
typedef long long ll;
typedef pair <int, int> pii;
typedef pair <ll, ll> pll;
  
#define precision(n) fixed << setprecision(n)
#define pb push_back
#define ub upper_bound
#define lb lower_bound
#define mp make_pair
#define eps (double)1e-9
#define PI 2*acos(0.0)
#define endl "\n"
#define sz(v) int((v).size())
#define all(v) v.begin(),v.end()
#define rall(v) v.rbegin(),v.rend()
#define do_not_disturb ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define OK cout << "OK" << endl;
  
inline bool isvowel(char ch){
    ch = tolower(ch);
    return (ch == 'a' || ch == 'e' || ch == 'i' || ch == 'o' || ch == 'u');
}
  
inline bool isprime(int n){
    if(n < 2 || (n%2 == 0 && n != 2)) return false;
    for(int i = 3; i*i <= n; i++)
        if(n%i == 0) return false;
    return true;
}
 
class Union{
    private:
        vector <int> saizu, link;
    public:
        Union(int n){
            saizu.assign(n, 1); link.resize(n); 
            iota(all(link), 0);
        }
        int find(int n){
            if(link[n] == n) return n;
            return link[n] = find(link[n]);
        }
        int same(int a, int b){
            return find(a) == find(b);
        }
        void unite(int a, int b){
            if(same(a, b)) return;
             
            a = find(a); b = find(b);
            if(saizu[a] < saizu[b]) swap(a, b);
             
            saizu[a] += saizu[b];
            link[b] = a;
        }
        int getsize(int a){
            return saizu[find(a)];
        }
};
 
const int mod = 1e9+7;
 
ll mode(ll a){
    a %= mod;
    if(a < 0) a += mod;
    return a;
}
 
ll subt(ll a, ll b){
    return mode(mode(a)-mode(b));
}
 
ll add(ll a, ll b){
    return mode(mode(a)+mode(b));
}
 
ll mult(ll a, ll b){
    return mode(mode(a)*mode(b));
}
 
ll binpow(ll a, ll b){
    ll res = 1;
    while(b){
        if(b&1) res = mult(res, a);
        a = mult(a, a);
        b >>= 1;
    }
    return res;
}

int main(){
    do_not_disturb
    
    int n, m, i, j;
    cin >> n >> m;
    int grid[n+1][m+1], pref[n+2][m+2], suff[n+2][m+2], up[n+2][m+2], down[n+2][m+2];
    
    for(i = 1; i <= n; i++){
        pref[i][0] = 0;
        suff[i][m+1] = m+1;
        for(j = 1; j <= m; j++){
            up[0][j] = 0;
            down[n+1][j] = n+1;
            char ch;
            cin >> ch;
            grid[i][j] = ch-'0';
        }
    }
    
    for(i = 1; i <= n; i++){
        for(j = 1; j <= m; j++){
            if(grid[i][j]) pref[i][j] = pref[i][j-1];
            else pref[i][j] = j;
        }
        for(j = m; j; j--){
            if(grid[i][j]) suff[i][j] = suff[i][j+1];
            else suff[i][j] = j;
        }
    }
    
    for(j = 1; j <= m; j++){
        for(i = 1; i <= n; i++){
            if(grid[i][j]) up[i][j] = up[i-1][j];
            else up[i][j] = i;
        }
        for(i = n; i; i--){
            if(grid[i][j]) down[i][j] = down[i+1][j];
            else down[i][j] = i;
        }
    }
    
    vector <int> res(m+1, 2e9);
    
    for(i = 1; i <= n; i++){
        int mnu = 2e9, mnd = 2e9;
        for(j = 1; j <= m; j++){
            if(grid[i][j]){
                mnu = min(mnu, i-up[i][j]);
                mnd = min(mnd, down[i][j]-i);
                res[j-pref[i][j]] = min(res[j-pref[i][j]], (mnu+mnd-1));
            }
            else{
                mnu = mnd = 2e9;
            }
        }
        mnu = mnd = 2e9;
        for(j = m; j; j--){
            if(grid[i][j]){
                mnu = min(mnu, i-up[i][j]);
                mnd = min(mnd, down[i][j]-i);
                res[suff[i][j]-j] = min(res[suff[i][j]-j], (mnu+mnd-1));
            }
            else{
                mnu = mnd = 2e9;
            }
        }
    }
    
    int to_consider = 2e9;
    for(i = 1; i <= n; i++){
        for(j = 1; j <= m; j++){
            if(grid[i][j]){
                to_consider = min(to_consider, suff[i][j]-pref[i][j]-1);
            }
        }
    }
    
    int ans = 0;
    for(j = 1; j <= to_consider; j++){
        ans = max(ans, res[j]*j);
    }
    cout << ans;
    
    return 0;
}

• Subtask 1: 90 / 100