CSES - Datatähti 2024 alku - Results
Submission details
Task:Uolevin kalansaalis
Sender:chaotic
Submission time:2023-11-08 22:10:53 +0200
Language:C++20
Status:READY
Result:100
Feedback
groupverdictscore
#1ACCEPTED37
#2ACCEPTED63
Test results
testverdicttimegroup
#1ACCEPTED0.00 s1, 2details
#2ACCEPTED0.00 s1, 2details
#3ACCEPTED0.00 s1, 2details
#4ACCEPTED0.00 s1, 2details
#5ACCEPTED0.00 s1, 2details
#6ACCEPTED0.00 s1, 2details
#7ACCEPTED0.00 s1, 2details
#8ACCEPTED0.00 s1, 2details
#9ACCEPTED0.00 s1, 2details
#10ACCEPTED0.00 s1, 2details
#11ACCEPTED0.00 s1, 2details
#12ACCEPTED0.00 s1, 2details
#13ACCEPTED0.00 s1, 2details
#14ACCEPTED0.00 s1, 2details
#15ACCEPTED0.00 s1, 2details
#16ACCEPTED0.40 s2details
#17ACCEPTED0.40 s2details
#18ACCEPTED0.47 s2details
#19ACCEPTED0.35 s2details
#20ACCEPTED0.40 s2details
#21ACCEPTED0.37 s2details
#22ACCEPTED0.37 s2details
#23ACCEPTED0.35 s2details
#24ACCEPTED0.39 s2details

Code

#include <algorithm>
#include <cassert>
#include <iostream>
#include <limits>
#include <sstream>
#include <vector>

static_assert(sizeof(int) == 4);

template<class T> struct array2d {
    std::vector<T> data;
    size_t const rows;
    size_t const cols;

    constexpr array2d(size_t rows_, size_t cols_)
        : data(rows_ * cols_, 0), rows(rows_), cols(cols_) {}

    constexpr T& operator()(size_t row, size_t col) {
        assert(row < rows);
        assert(col < cols);
        return data[row + col * rows];
    }
    constexpr T const& operator()(size_t row, size_t col) const {
        assert(row < rows);
        assert(col < cols);
        return data[row + col * rows];
    }
};

// Calculate sum in range [first, first + count)
int sum_between(auto const& arr, size_t row, size_t first, size_t count) {
    return arr(row, first + count) - arr(row, first);
}

auto create_diagonals(auto const& values, int const first_row_offset) {
    array2d<int> arr(values.rows + 1, values.cols + (values.rows - first_row_offset) / 2);

    auto col_of_next_row = [first_row_offset](size_t row, size_t col) {
        if (first_row_offset == 0) return row % 2 == 1 ? col : col - 1;
        return row % 2 == 0 ? col : col - 1;
    };

    auto colum_starting_at = [&](size_t row, size_t col) {
        assert(row == 0 || col == values.cols - 1);
        size_t const target_col = row == 0 ? col : values.cols + (row - first_row_offset) / 2;
        size_t target_row       = row + 1;

        //        arr(target_row++, target_col) = 0;

        while (true) {
            if (row >= values.rows) break;
            if (col + 1 == 0) break;
            arr(target_row, target_col) = arr(target_row - 1, target_col) + values(row, col);
            col                         = col_of_next_row(row, col);
            ++row;
            ++target_row;
        }
    };

    for (size_t col = 0; col < values.cols; ++col) colum_starting_at(0, col);

    for (size_t row = 1 + first_row_offset; row < values.rows; row += 2)
        colum_starting_at(row, values.cols - 1);

    return arr;
}

int get_diagonal_sum(
    auto const& diagonals, size_t row, size_t col, size_t count, int const first_row_offset
) {
    size_t target_column;
    if (first_row_offset == 0) {
        target_column = col + (row + 1) / 2;
    } else {
        target_column = col + row / 2;
    }

    return diagonals(row + count, target_column) - diagonals(row, target_column);
}

int do_search(
    int total, size_t const rows, size_t const cols, auto const& values, auto const& diags,
    int const first_row_offset
) {
    int result                    = std::numeric_limits<int>::min();
    size_t const biggest_triangle = std::min(rows, cols);

    for (size_t row = 0; row < rows; ++row) {
        for (size_t col = 0; col < cols; ++col) {
            int sum = values(row, col);
            result  = std::max(result, total - sum);

            //            if (col == 2 && row == 1) asm("int $3");

            for (size_t T = 2; T <= biggest_triangle; ++T) {
                if (row + T > rows) break;
                if (col + T > cols) break;

                sum    += get_diagonal_sum(diags, row, col + T - 1, T, first_row_offset);
                result  = std::max(result, total - sum);
            }
        }
    }

    return result;
}

int main() {
    //    std::stringstream input(R"(5 6 13
    //     1 1 K
    //     5 1 K
    //     2 2 H
    //     4 2 H
    //     5 2 H
    //     2 6 K
    //     3 3 H
    //     3 4 K
    //     3 5 H
    //     3 6 K
    //     4 4 K
    //     2 5 H
    //     5 5 H)");
    //    std::stringstream input(R"(
    //    4 4 4
    //    1 1 H
    //    3 3 K
    //    4 2 K
    //    4 3 K
    //            )");
    auto& input = std::cin;

    size_t rows, cols, k;
    input >> rows >> cols >> k;

    array2d<int> values(rows, cols);
    int total_sum = 0;

    for (size_t i = 0; i < k; ++i) {
        size_t x, y;
        char ch;
        input >> x >> y >> ch;
        values(x - 1, y - 1)  = ch == 'K' ? -10 : 1;
        total_sum            += ch == 'K' ? -10 : 1;
    }

    // ---------------------

    auto diags = create_diagonals(values, 0);

    int result = do_search(total_sum, rows, cols, values, diags, 0);

    //    Reverse each column
    for (size_t i = 0; i < cols; ++i) { std::reverse(&values(0, i), &values(rows - 1, i) + 1); }

    int const first_row_offset = rows % 2 == 0 ? 1 : 0;

    auto diags2 = create_diagonals(values, first_row_offset);

    result = std::max(result, do_search(total_sum, rows, cols, values, diags2, first_row_offset));

    std::cout << result << "\n";
}

Test details

Test 1

Group: 1, 2

Verdict: ACCEPTED

input
5 6 13
1 1 K
5 1 K
2 2 H
4 2 H
...

correct output
-16

user output
-16

Test 2

Group: 1, 2

Verdict: ACCEPTED

input
5 6 7
1 5 K
4 6 K
2 4 H
2 5 H
...

correct output
0

user output
0

Test 3

Group: 1, 2

Verdict: ACCEPTED

input
5 6 7
5 5 K
2 6 K
2 4 H
2 5 H
...

correct output
0

user output
0

Test 4

Group: 1, 2

Verdict: ACCEPTED

input
10 10 51
3 3 H
6 3 H
9 5 H
5 10 H
...

correct output
50

user output
50

Test 5

Group: 1, 2

Verdict: ACCEPTED

input
10 10 52
3 5 H
3 1 H
9 6 H
2 8 H
...

correct output
40

user output
40

Test 6

Group: 1, 2

Verdict: ACCEPTED

input
10 10 60
6 10 H
2 8 H
5 8 H
8 10 H
...

correct output
-15

user output
-15

Test 7

Group: 1, 2

Verdict: ACCEPTED

input
10 10 60
4 7 H
7 4 H
4 10 H
3 6 H
...

correct output
60

user output
60

Test 8

Group: 1, 2

Verdict: ACCEPTED

input
10 10 40
9 9 H
5 10 H
5 6 H
4 9 H
...

correct output
2

user output
2

Test 9

Group: 1, 2

Verdict: ACCEPTED

input
1 1 0

correct output
0

user output
0

Test 10

Group: 1, 2

Verdict: ACCEPTED

input
1 1 1
1 1 K

correct output
0

user output
0

Test 11

Group: 1, 2

Verdict: ACCEPTED

input
1 1 1
1 1 H

correct output
0

user output
0

Test 12

Group: 1, 2

Verdict: ACCEPTED

input
10 5 32
10 3 H
4 4 H
3 3 H
5 4 H
...

correct output
20

user output
20

Test 13

Group: 1, 2

Verdict: ACCEPTED

input
5 10 32
5 9 H
2 4 H
2 9 H
2 5 H
...

correct output
28

user output
28

Test 14

Group: 1, 2

Verdict: ACCEPTED

input
10 10 100
2 9 H
5 4 H
5 9 K
6 1 K
...

correct output
-439

user output
-439

Test 15

Group: 1, 2

Verdict: ACCEPTED

input
10 10 100
8 9 H
5 10 H
5 4 H
3 9 H
...

correct output
88

user output
88

Test 16

Group: 2

Verdict: ACCEPTED

input
500 500 125000
125 261 K
84 78 K
11 200 K
481 246 K
...

correct output
-624270

user output
-624270

Test 17

Group: 2

Verdict: ACCEPTED

input
500 500 125100
16 61 H
37 62 H
459 125 H
318 476 H
...

correct output
124020

user output
124020

Test 18

Group: 2

Verdict: ACCEPTED

input
500 500 249999
22 214 H
356 145 H
341 29 H
393 262 H
...

correct output
249999

user output
249999

Test 19

Group: 2

Verdict: ACCEPTED

input
500 500 32000
30 81 H
315 34 H
78 112 H
367 166 H
...

correct output
10126

user output
10126

Test 20

Group: 2

Verdict: ACCEPTED

input
500 500 126745
164 390 H
126 331 H
164 126 H
55 92 H
...

correct output
-104692

user output
-104692

Test 21

Group: 2

Verdict: ACCEPTED

input
500 500 71200
106 191 H
314 189 H
482 485 H
344 401 H
...

correct output
-335853

user output
-335853

Test 22

Group: 2

Verdict: ACCEPTED

input
500 500 67772
421 277 H
428 470 H
169 142 H
256 345 H
...

correct output
-208567

user output
-208567

Test 23

Group: 2

Verdict: ACCEPTED

input
500 500 27434
366 481 H
38 22 H
126 107 H
135 169 H
...

correct output
-57100

user output
-57100

Test 24

Group: 2

Verdict: ACCEPTED

input
500 500 93982
183 13 H
463 230 H
264 351 H
399 290 H
...

correct output
-52800

user output
-52800