Submission #1050731

#	Time	Username	Problem	Language	Result	Execution time	Memory
1050731		fryingduc	Bitaro the Brave (JOI19_ho_t1)	C++17	100 / 100	222 ms	115028 KiB

joi2019_ho_t1

#include "bits/stdc++.h"
using namespace std;

const int maxn = 3005;
int n, m;
int a[maxn][maxn];
int cr[maxn][maxn], cc[maxn][maxn];

int convert(char x) {
    if(x == 'J') return 0;
    if(x == 'O') return 1;
    return 2;
}
void solve() {
    cin >> n >> m;
    char ch;
    for(int i = 1; i <= n; ++i) {
        for(int j = 1; j <= m; ++j) {
            cin >> ch;
            a[i][j] = convert(ch);
        }
    }
    vector<int> cnt;
    for(int i = 1; i <= n; ++i) {
        for(int j = m; j; --j) {
            cr[i][j] = cr[i][j + 1] + (a[i][j] == 1);            
        }
    }
    for(int j = 1; j <= m; ++j) {
        for(int i = n; i; --i) {
            cc[i][j] = cc[i + 1][j] + (a[i][j] == 2);
        }
    }
    long long ans = 0;
    for(int i = 1; i <= n; ++i) {
        for(int j = 1; j <= m; ++j) {
            if(a[i][j] == 0) {
                ans += 1ll * cc[i][j] * cr[i][j];
            }
        }
    }
    cout << ans;
}
signed main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    
    solve();
    return 0;
}

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