Submission #704039

#	Time	Username	Problem	Language	Result	Execution time	Memory
704039		1075508020060209tc	Bitaro the Brave (JOI19_ho_t1)	C++14	100 / 100	273 ms	159440 KiB

joi2019_ho_t1

//#pragma GCC optimize("O3")
#include<bits/stdc++.h>
using namespace std;
#define int long long
#define X first
#define Y second
int n;int m;
string gr[5010];
int pso[3010][3010];
int psi[3010][3010];

signed main(){
cin.tie(0);
ios_base::sync_with_stdio(0);

cin>>n>>m;
for(int i=1;i<=n;i++){
    cin>>gr[i];
    gr[i]="*"+gr[i];
}

for(int j=1;j<=m;j++){
    for(int i=1;i<=n;i++){
        psi[i][j]=psi[i-1][j];
        if(gr[i][j]=='I'){
            psi[i][j]++;
        }
    }
}
for(int i=1;i<=n;i++){
    for(int j=1;j<=m;j++){
        pso[i][j]=pso[i][j-1];
        if(gr[i][j]=='O'){
            pso[i][j]++;
        }
    }
}
int ans=0;
for(int i=1;i<=n;i++){
    for(int j=1;j<=m;j++){
        if(gr[i][j]!='J'){continue;}
        ans+=(pso[i][m]-pso[i][j])*(psi[n][j]-psi[i][j]);
    }
}
cout<<ans<<endl;

}

• Subtask 1: 20 / 20
• Subtask 2: 30 / 30
• Subtask 3: 50 / 50