Submission #1277001

#	Time	Username	Problem	Language	Result	Execution time	Memory
1277001		LmaoLmao	Bitaro the Brave (JOI19_ho_t1)	C++20	100 / 100	216 ms	150400 KiB

joi2019_ho_t1

#include<bits/stdc++.h>
#define int long long
#define fi first
#define se second

using namespace std;
using ll = long long;
using ii = pair<int,int>;
using aa = array<int,3>;

char a[3005][3005];
int O[3005][3005];
int I[3005][3005];

signed main() 
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL); cout.tie(NULL);
    int n,m;
    cin >> n >> m;
    for(int i=1;i<=n;i++) {
      for(int j=1;j<=m;j++) {
        cin >> a[i][j];
        O[i][j]=O[i][j-1];
        if(a[i][j]=='O') {
          O[i][j]++;
        }
        I[i][j]=I[i-1][j];
        if(a[i][j]=='I') {
          I[i][j]++;
        }
      } 
    }
    int ans=0;
    for(int i=1;i<=n;i++) {
      for(int j=1;j<=m;j++) {
        if(a[i][j]=='J') {
          ans+=(O[i][m]-O[i][j])*(I[n][j]-I[i][j]);
        }
      }
    }
    cout << ans;
    return 0;
}

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