Submission #1232274

#TimeUsernameProblemLanguageResultExecution timeMemory
1232274CrabCNHBitaro the Brave (JOI19_ho_t1)C++20
100 / 100
379 ms206832 KiB
#include <bits/stdc++.h>

#define task     "BriantheCrab"

#define int    long long
#define pii    pair <int, int>
#define fi     first
#define se     second
#define szf    sizeof
#define sz(s)  (int)((s).size())
#define all(v) (v).begin(), (v).end()

typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;

using namespace std;

template <class T> void minimize (T &t, T f) {if (t > f) t = f;}
template <class T> void maximize (T &t, T f) {if (t < f) t = f;}

const int maxN = 3e3 + 5;
const int inf = 1e18 + 7;
const int mod = 1e9 + 7;

// khong tu code thi khong kha len duoc dau

int n, m;
char a[maxN][maxN];
int pfs[maxN][maxN][2]; // o, i
vector <pii> posJ;

inline int get (int xU, int yU, int xD, int yD, int t) {
    return pfs[xD][yD][t] - pfs[xD][yU - 1][t] - pfs[xU - 1][yD][t] + pfs[xU - 1][yU - 1][t];
}

void solve () {
    int n, m;
    cin >> n >> m;
    for (int i = 1; i <= n; i ++) {
        for (int j = 1; j <= m; j ++) {
            cin >> a[i][j];
            if (a[i][j] == 'J') {
                posJ.push_back ({i, j});
            }
        }
    }
    for (int i = 1; i <= n; i ++) {
        for (int j = 1; j <= m; j ++) {
            pfs[i][j][0] = pfs[i - 1][j][0] + pfs[i][j - 1][0] - pfs[i - 1][j - 1][0] + (a[i][j] == 'O');
            pfs[i][j][1] = pfs[i - 1][j][1] + pfs[i][j - 1][1] - pfs[i - 1][j - 1][1] + (a[i][j] == 'I');
        }
    }
    int res = 0;
    for (auto [x, y] : posJ) {
        res += get (x, y + 1, x, m, 0) * get (x + 1, y, n, y, 1);
        //cout << x << ' ' << y << ' ' << get (x, y + 1, x, m, 0) <<' ' << get (x + 1, y, n, y, 1) << '\n';
    }
    cout << res;
    return;
}

signed main () {
    cin.tie (nullptr) -> sync_with_stdio (false);
    if (fopen (task".inp", "r")) {
        freopen (task".inp", "r", stdin);
        freopen (task".out", "w", stdout);
    }
    int t = 1;
    //cin >> t;
    while (t --) {
        solve ();
    } 
    return 0;
}
// thfv

Compilation message (stderr)

joi2019_ho_t1.cpp: In function 'int main()':
joi2019_ho_t1.cpp:66:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   66 |         freopen (task".inp", "r", stdin);
      |         ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
joi2019_ho_t1.cpp:67:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   67 |         freopen (task".out", "w", stdout);
      |         ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
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