Submission #1071484

#	Time	Username	Problem	Language	Result	Execution time	Memory
1071484		Plurm	Cultivation (JOI17_cultivation)	C++11	15 / 100	1002 ms	600 KiB

cultivation

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

int r, c;
bitset<1600> moveleft(bitset<1600> mask) {
    for (int i = 0; i < r; i++)
        mask[i * c] = false;
    return mask >> 1;
}
bitset<1600> moveright(bitset<1600> mask) {
    for (int i = 0; i < r; i++)
        mask[i * c + c - 1] = false;
    return mask << 1;
}
bitset<1600> moveup(bitset<1600> mask) {
    for (int i = 0; i < c; i++)
        mask[i] = false;
    mask >>= c;
    for (int i = 0; i < c; i++)
        mask[(r - 1) * c + i] = false;
    return mask;
}
bitset<1600> movedown(bitset<1600> mask) {
    for (int i = 0; i < c; i++)
        mask[(r - 1) * c + i] = false;
    return mask << c;
}
int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cin >> r >> c;
    int n;
    cin >> n;
    vector<pair<int, int>> pts;
    for (int i = 0; i < n; i++) {
        int x, y;
        cin >> x >> y;
        swap(x, y);
        pts.push_back({x, y});
    }
    swap(r, c);
    bitset<1600> init(0);
    for (auto p : pts) {
        if ((p.first - 1) * c + p.second - 1 < 1600)
            init[(p.first - 1) * c + p.second - 1] = true;
    }
    for (int ans = 0; ans <= 100; ans++) {
        for (int p = 0; p <= c && p <= ans; p++) {
            for (int q = 0; q <= c && q <= ans; q++) {
                for (int s = 0; s <= r && s <= ans; s++) {
                    int t = ans - p - q - s;
                    if (t < 0 || t > r)
                        continue;
                    auto state = init;
                    int comm = max({p, q, s, t});
                    for (int _ = 0; _ < comm; _++) {
                        if (_ < p)
                            state |= moveleft(state);
                        if (_ < s)
                            state |= moveup(state);
                        if (_ < q)
                            state |= moveright(state);
                        if (_ < t)
                            state |= movedown(state);
                    }
                    if (state.count() >= r * c) {
                        cout << ans << endl;
                        return 0;
                    }
                }
            }
        }
    }
    cout << c - 1 + r - 1 << endl;
    return 0;
}

Compilation message (stderr)

cultivation.cpp: In function 'int main()':
cultivation.cpp:66:39: warning: comparison of integer expressions of different signedness: 'std::size_t' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   66 |                     if (state.count() >= r * c) {
      |                         ~~~~~~~~~~~~~~^~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 0 / 15
• Subtask 4: 0 / 30
• Subtask 5: 0 / 20
• Subtask 6: 0 / 20