CSES - Datatähti 2024 alku

Submission details
Task:	Uolevin kalansaalis
Sender:	chaotic
Submission time:	2023-11-08 22:10:53 +0200
Language:	C++ (C++20)
Status:	READY
Result:	100

Feedback
group	verdict	score
#1	ACCEPTED	37
#2	ACCEPTED	63

Test results
test	verdict	time	group
#1	ACCEPTED	0.00 s	1, 2	details
#2	ACCEPTED	0.00 s	1, 2	details
#3	ACCEPTED	0.00 s	1, 2	details
#4	ACCEPTED	0.00 s	1, 2	details
#5	ACCEPTED	0.00 s	1, 2	details
#6	ACCEPTED	0.00 s	1, 2	details
#7	ACCEPTED	0.00 s	1, 2	details
#8	ACCEPTED	0.00 s	1, 2	details
#9	ACCEPTED	0.00 s	1, 2	details
#10	ACCEPTED	0.00 s	1, 2	details
#11	ACCEPTED	0.00 s	1, 2	details
#12	ACCEPTED	0.00 s	1, 2	details
#13	ACCEPTED	0.00 s	1, 2	details
#14	ACCEPTED	0.00 s	1, 2	details
#15	ACCEPTED	0.00 s	1, 2	details
#16	ACCEPTED	0.40 s	2	details
#17	ACCEPTED	0.40 s	2	details
#18	ACCEPTED	0.47 s	2	details
#19	ACCEPTED	0.35 s	2	details
#20	ACCEPTED	0.40 s	2	details
#21	ACCEPTED	0.37 s	2	details
#22	ACCEPTED	0.37 s	2	details
#23	ACCEPTED	0.35 s	2	details
#24	ACCEPTED	0.39 s	2	details

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 ...` view save

correct output
`-16` view save

user output
`-16` view save

Test 2

Group: 1, 2

Verdict: ACCEPTED

input
`5 6 7 1 5 K 4 6 K 2 4 H 2 5 H ...` view save

correct output
`0` view save

user output
`0` view save

Test 3

Group: 1, 2

Verdict: ACCEPTED

input
`5 6 7 5 5 K 2 6 K 2 4 H 2 5 H ...` view save

correct output
`0` view save

user output
`0` view save

Test 4

Group: 1, 2

Verdict: ACCEPTED

input
`10 10 51 3 3 H 6 3 H 9 5 H 5 10 H ...` view save

correct output
`50` view save

user output
`50` view save

Test 5

Group: 1, 2

Verdict: ACCEPTED

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

correct output
`40` view save

user output
`40` view save

Test 6

Group: 1, 2

Verdict: ACCEPTED

input
`10 10 60 6 10 H 2 8 H 5 8 H 8 10 H ...` view save

correct output
`-15` view save

user output
`-15` view save

Test 7

Group: 1, 2

Verdict: ACCEPTED

input
`10 10 60 4 7 H 7 4 H 4 10 H 3 6 H ...` view save

correct output
`60` view save

user output
`60` view save

Test 8

Group: 1, 2

Verdict: ACCEPTED

input
`10 10 40 9 9 H 5 10 H 5 6 H 4 9 H ...` view save

correct output
`2` view save

user output
`2` view save

Test 9

Group: 1, 2

Verdict: ACCEPTED

input
`1 1 0` view save

correct output
`0` view save

user output
`0` view save

Test 10

Group: 1, 2

Verdict: ACCEPTED

input
`1 1 1 1 1 K` view save

correct output
`0` view save

user output
`0` view save

Test 11

Group: 1, 2

Verdict: ACCEPTED

input
`1 1 1 1 1 H` view save

correct output
`0` view save

user output
`0` view save

Test 12

Group: 1, 2

Verdict: ACCEPTED

input
`10 5 32 10 3 H 4 4 H 3 3 H 5 4 H ...` view save

correct output
`20` view save

user output
`20` view save

Test 13

Group: 1, 2

Verdict: ACCEPTED

input
`5 10 32 5 9 H 2 4 H 2 9 H 2 5 H ...` view save

correct output
`28` view save

user output
`28` view save

Test 14

Group: 1, 2

Verdict: ACCEPTED

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

correct output
`-439` view save

user output
`-439` view save

Test 15

Group: 1, 2

Verdict: ACCEPTED

input
`10 10 100 8 9 H 5 10 H 5 4 H 3 9 H ...` view save

correct output
`88` view save

user output
`88` view save

Test 16

Group: 2

Verdict: ACCEPTED

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

correct output
`-624270` view save

user output
`-624270` view save

Test 17

Group: 2

Verdict: ACCEPTED

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

correct output
`124020` view save

user output
`124020` view save

Test 18

Group: 2

Verdict: ACCEPTED

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

correct output
`249999` view save

user output
`249999` view save

Test 19

Group: 2

Verdict: ACCEPTED

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

correct output
`10126` view save

user output
`10126` view save

Test 20

Group: 2

Verdict: ACCEPTED

input
`500 500 126745 164 390 H 126 331 H 164 126 H 55 92 H ...` view save

correct output
`-104692` view save

user output
`-104692` view save

Test 21

Group: 2

Verdict: ACCEPTED

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

correct output
`-335853` view save

user output
`-335853` view save

Test 22

Group: 2

Verdict: ACCEPTED

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

correct output
`-208567` view save

user output
`-208567` view save

Test 23

Group: 2

Verdict: ACCEPTED

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

correct output
`-57100` view save

user output
`-57100` view save

Test 24

Group: 2

Verdict: ACCEPTED

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

correct output
`-52800` view save

user output
`-52800` view save

Datatähti 2024 alku

Uolevin kalansaalis

Code

Test details

Test 1

Test 2

Test 3

Test 4

Test 5

Test 6

Test 7

Test 8

Test 9

Test 10

Test 11

Test 12

Test 13

Test 14

Test 15

Test 16

Test 17

Test 18

Test 19

Test 20

Test 21

Test 22

Test 23

Test 24

Tasks

Submissions (chaotic)