Submission #1169525

#	Time	Username	Problem	Language	Result	Execution time	Memory
1169525		rayan_bd	Bitaro the Brave (JOI19_ho_t1)	C++20	100 / 100	255 ms	150516 KiB

joi2019_ho_t1

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;

typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> pbds; 


#define getar(ar,n) for(ll i=0;i<n;++i) cin>>ar[i]
#define show(n) cout<<n<<'\n'
#define all(v) v.begin(), v.end()
#define br cout<<"\n"
#define pb push_back
#define nl '\n'
#define yes cout<<"YES\n"
#define no cout<<"NO\n"
#define ret return
#define ll long long
#define ld long double
#define sza(x) ((int)x.size())
#define fi first
#define se second

const int mxN = 3005;
const ll MOD = 1e9 + 7;
const ll INF = 1e9;
const ld EPS = 1e-9;

char grid[mxN][mxN];
ll row_sum[mxN][mxN],col_sum[mxN][mxN];

void lets_go() {
	ll n,m,ans=0;cin>>n>>m;
	for(ll i=1;i<=n;++i){
		string str;cin>>str;
		for(ll j=1;j<=m;++j){
			grid[i][j]=str[j-1];
		}
	}

	for(ll i=1;i<=n;++i){
		for(ll j=m;j>=1;--j){
			row_sum[i][j]=row_sum[i][j+1]+(grid[i][j]=='O');
		}
	}

	for(ll j=1;j<=m;++j){
		for(ll i=n;i>=1;--i){
			col_sum[i][j]=col_sum[i+1][j]+(grid[i][j]=='I');
		}
	}

	for(ll i=1;i<=n;++i){
		for(ll j=1;j<=m;++j){
			if(grid[i][j]=='J') ans+=col_sum[i][j]*row_sum[i][j];
		}
	}

	show(ans);
}

int main() {
    
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    
    lets_go();

    return 0;
}

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