Submission #1265458

#	Time	Username	Problem	Language	Result	Execution time	Memory
1265458		trinm01	Bitaro the Brave (JOI19_ho_t1)	C++20	100 / 100	276 ms	150520 KiB

joi2019_ho_t1

// #pragma GCC optimize("O3")
// #pragma GCC optimization("Ofast,unroll-loops")
// #pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#include <bits/stdc++.h>
using namespace std;

#define int long long 
#define ll long long
#define FOR(i, l, r) for (int i = (l); i <= (r); i++)
#define FOD(i, r, l) for (int i = (r); i >= (l); i--)
#define fi first
#define se second
#define pii pair<int, int>

const ll mod = 1e9 + 7;
const int MAXN = 3e3 + 5;
const ll oo = 1e18+7;  
const int base = 0;

int m, n;
char a[MAXN][MAXN];
int O[MAXN][MAXN], I[MAXN][MAXN];

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

    // freopen("test.txt", "r", stdin);
    // freopen("o2.out", "w", stdout); 

    // if(fopen(".inp", "r")){
    //     freopen(".inp", "r", stdin);
    //     freopen(".out", "w", stdout);
    // }   

    cin >> m >> n;
    FOR(i, 1, m){
        string s;
        cin >> s;
        FOR(j, 1, n){
            a[i][j]=s[j-1];
        }
    }

    FOR(i, 1, m){
        FOR(j, 1, n){
            O[i][j]=O[i][j-1];
            if(a[i][j]=='O'){
                O[i][j]++;
            }
        }
    }
    FOR(j, 1, n){
        FOR(i, 1, m){
            I[i][j]=I[i-1][j];
            if(a[i][j]=='I'){
                I[i][j]++;
            }
        }
    }

    int ans=0;
    FOR(i, 1, m){
        FOR(j, 1, n){
            if(a[i][j]=='J'){
                ans+=(O[i][n]-O[i][j-1])*(I[m][j]-I[i-1][j]);
            }
        }
    }
    cout << ans;
    
    return 0;
}

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