10284 - Chessboard in FEN

#include <bits/stdc++.h>

using namespace std;

#define ll long long
#define endl '\n'
#define sz(x) int(x.size())
#define all(x) x.begin(), x.end()

int main() {
    ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);

    string s;
    while (cin >> s) {
        if (s == "") break;
        int row = 0, col = 0;
        auto valid = [](int i, int j) -> bool {
            return 0 <= i && i < 8 && 0 <= j && j < 8;
        };
        vector<vector<bool>> under_attack(8, vector<bool>(8, 0));
        vector<vector<bool>> occ(8, vector<bool>(8, 0));
        for (int J = 0; J < sz(s); J++) {
            if (s[J] == '/') row++, col = 0;
            else  {
                if (isdigit(s[J])) col += s[J] - '0';
                else {
                    occ[row][col] = 1;
                    col++;
                }
            }
        }
        row = 0, col = 0;
        for (int J = 0; J < sz(s); J++) {
            if (s[J] == '/') row++, col = 0;
            else {
                if (isdigit(s[J])) col += s[J] - '0';
                else {
                    if (s[J] == 'q' || s[J] == 'Q') { // Queen
                        for (int i = 1; i <= 8; i++) {
                            if (valid(row + i, col + i)) {
                                if (occ[row + i][col + i]) break;
                                under_attack[row + i][col + i] = 1;
                            }
                        }
                        for (int i = 1; i <= 8; i++) {
                            if (valid(row - i, col - i)) {
                                if (occ[row - i][col - i]) break;
                                under_attack[row - i][col - i] = 1;
                            }
                        }

                        for (int i = 1; i <= 8; i++) {
                            if (valid(row + i, col)) {
                                if (occ[row + i][col]) break;
                                under_attack[row + i][col] = 1;
                            }
                        }

                        for (int i = 1; i <= 8; i++) {
                            if (valid(row - i, col)) {
                                if (occ[row - i][col]) break;
                                under_attack[row - i][col] = 1;
                            }
                        }

                        for (int i = 1; i <= 8; i++) {
                            if (valid(row, col + i)) {
                                if (occ[row][col + i]) break;
                                under_attack[row][col + i] = 1;
                            }
                        }
                        for (int i = 1; i <= 8; i++) {
                            if (valid(row, col - i)) {
                                if (occ[row][col - i]) break;
                                under_attack[row][col - i] = 1;
                            }
                        }

                        for (int i = 1; i <= 8; i++) {
                            if (valid(row - i, col + i)) {
                                if (occ[row - i][col + i]) break;
                                under_attack[row - i][col + i] = 1;
                            }
                        }
                        for (int i = 1; i <= 8; i++) {
                            if (valid(row + i, col - i)) {
                                if (occ[row + i][col - i]) break;
                                under_attack[row + i][col - i] = 1;
                            }
                        }
                    }
                    else if (s[J] == 'p' || s[J] == 'P') {
                        if (valid(row + (s[J] == 'p' ? 1 : -1), col + 1))
                            under_attack[row + (s[J] == 'p' ? 1 : -1)][col + 1] = 1;
                        if (valid(row + (s[J] == 'p' ? 1 : -1), col - 1))
                            under_attack[row + (s[J] == 'p' ? 1 : -1)][col - 1] = 1;
                    }
                    else if (s[J] == 'r' || s[J] == 'R') {
                        for (int i = 1; i <= 8; i++) {
                            if (valid(row + i, col)) {
                                if (occ[row + i][col]) break;
                                under_attack[row + i][col] = 1;
                            }
                        }

                        for (int i = 1; i <= 8; i++) {
                            if (valid(row - i, col)) {
                                if (occ[row - i][col]) break;
                                under_attack[row - i][col] = 1;
                            }
                        }

                        for (int i = 1; i <= 8; i++) {
                            if (valid(row, col + i)) {
                                if (occ[row][col + i]) break;
                                under_attack[row][col + i] = 1;
                            }
                        }
                        for (int i = 1; i <= 8; i++) {
                            if (valid(row, col - i)) {
                                if (occ[row][col - i]) break;
                                under_attack[row][col - i] = 1;
                            }
                        }

                    }
                    else if (s[J] == 'b' || s[J] == 'B') {
                        for (int i = 1; i <= 8; i++) {
                            if (valid(row + i, col + i)) {
                                if (occ[row + i][col + i]) break;
                                under_attack[row + i][col + i] = 1;
                            }
                        }
                        for (int i = 1; i <= 8; i++) {
                            if (valid(row - i, col - i)) {
                                if (occ[row - i][col - i]) break;
                                under_attack[row - i][col - i] = 1;
                            }
                        }

                        for (int i = 1; i <= 8; i++) {
                            if (valid(row - i, col + i)) {
                                if (occ[row - i][col + i]) break;
                                under_attack[row - i][col + i] = 1;
                            }
                        }
                        for (int i = 1; i <= 8; i++) {
                            if (valid(row + i, col - i)) {
                                if (occ[row + i][col - i]) break;
                                under_attack[row + i][col - i] = 1;
                            }
                        }
                    }
                    else if (s[J] == 'n' || s[J] == 'N') {
                        vector<pair<int, int>> knight_moves = {
                            {2, 1}, {2, -1}, {-2, 1}, {-2, -1},
                            {1, 2}, {-1, 2}, {1, -2}, {-1, -2}
                        };
                        for (auto & it : knight_moves) {
                            int dx = it.first + row, dy = it.second + col;
                            if (valid(dx, dy)) under_attack[dx][dy] = 1;
                        }
                    }
                    else if (s[J] == 'k' || s[J] == 'K') {
                        for (int i = -1; i < 2; i++) {
                            for (int j = -1; j < 2; j++) {
                                int dx = row + i, dy = col + j;
                                if (valid(dx, dy)) under_attack[dx][dy] = 1;
                            }
                        }
                    }
                    under_attack[row][col] = 1;
                    col++;
                }
            }
        }
        int cnt = 0;
        for (int i = 0; i < 8; i++) {
            for (int j = 0; j < 8; j++) {
                cnt += (under_attack[i][j] == 0);
            }
        }
        cout << cnt << endl;
        s = "";
    }
}