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Submission #516363

# Submission time Handle Problem Language Result Execution time Memory
516363 2022-01-21T08:23:18 Z Jomnoi Collecting Mushrooms (NOI18_collectmushrooms) C++17
100 / 100
 68 ms 29636 KB 
#include <bits/stdc++.h>
#define DEBUG 0
using namespace std;

vector <vector <char>> a;

class Fenwick {
    protected :
        int R, C;
        vector <vector <int>> fenwick;
    public :
        Fenwick(int r, int c) : R(r), C(c) {
            fenwick.resize(r + 10, vector <int> (c + 10, 0));
        } 

        int lsb(int x) {
            return x & -x;
        }

        void update(int x, int y, int val) {
            for(; x <= R; x += lsb(x)) {
                for(int idx = y; idx <= C; idx += lsb(idx)) {
                    fenwick[x][idx] += val;
                }
            }
        }

        int query(int x, int y) {
            int res = 0;
            for(; x > 0; x -= lsb(x)) {
                for(int idx = y; idx > 0; idx -= lsb(idx)) {
                    res += fenwick[x][idx];
                }
            }
            return res;
        }
};

int main() {
    int R, C, D, K;
    scanf(" %d %d %d %d", &R, &C, &D, &K);
    a.resize(R + 10, vector <char> (C + 10));
    for(int i = 1; i <= R; i++) {
        for(int j = 1; j <= C; j++) {
            scanf(" %c", &a[i][j]);
        }
    }

    Fenwick fw(R, C);
    for(int i = 1; i <= R; i++) {
        for(int j = 1; j <= C; j++) {
            if(a[i][j] == 'S') {
                int min_x = max(1, i - D), max_x = min(R + 1, i + D + 1);
                int min_y = max(1, j - D), max_y = min(C + 1, j + D + 1);
                fw.update(min_x, min_y, 1);
                fw.update(max_x, min_y, -1);
                fw.update(min_x, max_y, -1);
                fw.update(max_x, max_y, 1);
            }
        }
    }

    if(DEBUG) {
        cout << "Debugging :\n";
        for(int i = 1; i <= R; i++) {
            for(int j = 1; j <= C; j++) {
                cout << fw.query(i, j) << " ";
            }
            cout << endl;
        }
    }

    int ans = 0;
    for(int i = 1; i <= R; i++) {
        for(int j = 1; j <= C; j++) {
            if(a[i][j] == 'M' and fw.query(i, j) >= K) {
                ans++;
            }
        }
    }
    cout << ans;
    return 0;
}

Compilation message

mushrooms.cpp: In function 'int main()':
mushrooms.cpp:41:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   41 |     scanf(" %d %d %d %d", &R, &C, &D, &K);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
mushrooms.cpp:45:18: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   45 |             scanf(" %c", &a[i][j]);
      |             ~~~~~^~~~~~~~~~~~~~~~~

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 1 ms 292 KB Output is correct
3 Correct 1 ms 280 KB Output is correct
4 Correct 1 ms 272 KB Output is correct
5 Correct 1 ms 204 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 1 ms 292 KB Output is correct
3 Correct 1 ms 280 KB Output is correct
4 Correct 1 ms 272 KB Output is correct
5 Correct 1 ms 204 KB Output is correct
6 Correct 1 ms 288 KB Output is correct
7 Correct 1 ms 204 KB Output is correct
8 Correct 1 ms 292 KB Output is correct
9 Correct 1 ms 280 KB Output is correct
10 Correct 1 ms 288 KB Output is correct

Subtask #3
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 2 ms 292 KB Output is correct
3 Correct 1 ms 332 KB Output is correct
4 Correct 1 ms 204 KB Output is correct
5 Correct 1 ms 332 KB Output is correct

Subtask #4
23.0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 1452 KB Output is correct
2 Correct 16 ms 1476 KB Output is correct
3 Correct 12 ms 1836 KB Output is correct
4 Correct 10 ms 1484 KB Output is correct
5 Correct 11 ms 1580 KB Output is correct

Subtask #5
19.0 / 19.0

# Verdict Execution time Memory Grader output
1 Correct 43 ms 29624 KB Output is correct
2 Correct 37 ms 29628 KB Output is correct
3 Correct 42 ms 29636 KB Output is correct
4 Correct 51 ms 29624 KB Output is correct
5 Correct 39 ms 29616 KB Output is correct

Subtask #6
21.0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 1 ms 292 KB Output is correct
3 Correct 1 ms 280 KB Output is correct
4 Correct 1 ms 272 KB Output is correct
5 Correct 1 ms 204 KB Output is correct
6 Correct 1 ms 288 KB Output is correct
7 Correct 1 ms 204 KB Output is correct
8 Correct 1 ms 292 KB Output is correct
9 Correct 1 ms 280 KB Output is correct
10 Correct 1 ms 288 KB Output is correct
11 Correct 1 ms 204 KB Output is correct
12 Correct 2 ms 292 KB Output is correct
13 Correct 1 ms 332 KB Output is correct
14 Correct 1 ms 204 KB Output is correct
15 Correct 1 ms 332 KB Output is correct
16 Correct 12 ms 1452 KB Output is correct
17 Correct 16 ms 1476 KB Output is correct
18 Correct 12 ms 1836 KB Output is correct
19 Correct 10 ms 1484 KB Output is correct
20 Correct 11 ms 1580 KB Output is correct
21 Correct 43 ms 29624 KB Output is correct
22 Correct 37 ms 29628 KB Output is correct
23 Correct 42 ms 29636 KB Output is correct
24 Correct 51 ms 29624 KB Output is correct
25 Correct 39 ms 29616 KB Output is correct
26 Correct 42 ms 5936 KB Output is correct
27 Correct 35 ms 3236 KB Output is correct
28 Correct 68 ms 3928 KB Output is correct
29 Correct 53 ms 3780 KB Output is correct
30 Correct 33 ms 5220 KB Output is correct