Submission #1554113

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Source Code Expand

#include <bits/stdc++.h>
using namespace std;
#define int long long
using ll=long long;
using vi=vector<int>;
using pii=pair<int,int>;
#define ALL(c) begin(c),end(c)
#define RALL(c) rbegin(c),rend(c)
#define ITR(i,b,e) for(auto i=(b);i!=(e);++i)
#define FORE(x,c) for(auto &x:c)
#define REPF(i,a,n) for(int i=a,i##len=(int)(n);i<i##len;++i)
#define REP(i,n) REPF(i,0,n)
#define REPR(i,n) for(int i=(int)(n);i>=0;--i)
#define SZ(c) ((int)c.size())
#define CONTAIN(c,x) (c.find(x)!=end(c))
#define OUTOFRANGE(y,x,h,w) (y<0||x<0||y>=h||x>=w)
#define dump(...)
const int DX[9]={0,1,0,-1,1,1,-1,-1,0},DY[9]={-1,0,1,0,-1,1,1,-1,0};
#define INF (1001001001)
#define INFLL (1001001001001001001ll)
template<class T> ostream& operator << (ostream &os,const vector<T> &v) {
    ITR(i,begin(v),end(v)) os << *i << (i==end(v)-1 ? "" : "\n"); return os; }
template<class T> istream& operator >> (istream &is,vector<T> &v) {
    ITR(i,begin(v),end(v)) is >> *i; return is; }
template<class T> istream& operator >> (istream &is, pair<T,T> &p) {
        is >> p.first >> p.second; return is; }
template<class T>bool chmax(T &a,const T &b) {if(a<b) {a=b;return 1;} return 0;}
template<class T>bool chmin(T &a,const T &b) {if(b<a) {a=b;return 1;} return 0;}
//------------------------------------------------------------------------------
struct before_main_function {
    before_main_function() {
        #ifdef int
            #undef INF
            #define INF INFLL
            #define stoi stoll
        #endif
        cin.tie(0);ios::sync_with_stdio(false);
        cout<<setprecision(15)<<fixed;
        // #define endl "\n"
    }
} before_main_function;
//------------------8<------------------------------------8<--------------------

signed main() {
    int H,W;
    cin>>H>>W;
    vector<vector<int>> c(H,vector<int>(W));
    vector<vector<int>> bl(H,vector<int>(W,0));
    vector<vector<int>> wh(H,vector<int>(W,0));
    cin>>c;

    REP(i,H) {
        REP(j,W) {
            if(i%2==j%2) {
                bl[i][j]=c[i][j];
            } else {
                wh[i][j]=c[i][j];
            }
        }
    }

    REP(i,H) {
        REPF(j,1,W) {
            bl[i][j]+=bl[i][j-1];
            wh[i][j]+=wh[i][j-1];
        }
    }
    REP(j,W) {
        REPF(i,1,H) {
            bl[i][j]+=bl[i-1][j];
            wh[i][j]+=wh[i-1][j];
        }
    }

    int ans=0;
    REP(i,H) {
        REP(j,W) {
            REPF(k,i,H) {
                REPF(l,j,W) {
                    int BL=bl[k][l];
                    int WH=wh[k][l];
                    if(i>0) {
                        BL-=bl[i-1][l];
                        WH-=wh[i-1][l];
                    }
                    if(j>0) {
                        BL-=bl[k][j-1];
                        WH-=wh[k][j-1];
                    }
                    if(i>0 && j>0) {
                        BL+=bl[i-1][j-1];
                        WH+=wh[i-1][j-1];
                    }

                    if(BL==WH) {
                        chmax(ans,(k-i+1)*(l-j+1));
                    }
                }
            }
        }
    }
    cout<<ans<<endl;
    return 0;
}

Submission Info

Judge Result