Submission #482564

#	Time	Username	Problem	Language	Result	Execution time	Memory
482564		jalsol	Bitaro the Brave (JOI19_ho_t1)	C++17	100 / 100	113 ms	88480 KiB

joi2019_ho_t1

#ifdef LOCAL
#include "local.h"
#else
#include <bits/stdc++.h>
#define debug(...)
#define DB(...)
#endif

using namespace std;

const bool __initialization = []() {
    cin.tie(nullptr)->sync_with_stdio(false);
#define TASK "empty"
    if (fopen(TASK".inp", "r")) {
        (void)(!freopen(TASK".inp", "r", stdin));
        (void)(!freopen(TASK".out", "w", stdout)); }
    cout << setprecision(12) << fixed;
    return true;
}();

using ll = long long;
using ld = long double;

#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()

#define For(i, l, r) for (int i = (l); i <= (r); ++i)
#define Ford(i, r, l) for (int i = (r); i >= (l); --i)
#define Rep(i, n) For (i, 0, (n) - 1)
#define Repd(i, n) Ford (i, (n) - 1, 0)
#define Fe(...) for (auto __VA_ARGS__)

template <class C> inline int isz(const C& c) { return static_cast<int>(c.size()); }
template <class T> inline bool chmin(T& a, const T& b) { return (a > b) ? a = b, true : false; }
template <class T> inline bool chmax(T& a, const T& b) { return (a < b) ? a = b, true : false; }

constexpr ld eps = 1e-9;
constexpr int inf = 1e9;
constexpr ll linf = 1e18;

// =============================================================================

constexpr int maxn = 3000 + 5;

int n, m;
char a[maxn][maxn];

enum { J, O, I };
constexpr const char* c = "JOI";
int pref[3][maxn][maxn];

int get(int t, int x, int y, int u, int v) {
    return pref[t][u][v]
         - pref[t][x - 1][v]
         - pref[t][u][y - 1]
         + pref[t][x - 1][y - 1];
}

signed main() {
    cin >> n >> m;
    For (i, 1, n) cin >> (a[i] + 1);

    For (i, 1, n) {
        For (j, 1, m) {
            For (k, 1, 2) {
                pref[k][i][j] = pref[k][i - 1][j]
                              + pref[k][i][j - 1]
                              - pref[k][i - 1][j - 1]
                              + (a[i][j] == c[k]);
            }
        }
    }

    ll ans = 0;

    For (i, 1, n) {
        For (j, 1, m) {
            if (a[i][j] != 'J') continue;

            int cntO = get(O, i, j + 1, i, m);
            int cntI = get(I, i + 1, j, n, j);

            ans += 1LL * cntO * cntI;
        }
    }

    cout << ans << '\n';
}

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