585B - Phillip and Trains - CodeForces Solution

#include <cstdio>
using namespace std;

char field[3][105];
int n;

bool dfs(int row, int col, bool climbed) {
    if (row < 0 || row > 2) {
        return false;
    }
    if (col >= n) {
        return true;
    }
    if (climbed) {
        return field[row][col] == '.' && field[row][col + 1] == '.' && field[row][col + 2] == '.' && dfs(row, col + 2, false);
    }
    field[row][col] = 'A';
    return field[row][col + 1] == '.' && (dfs(row - 1, col + 1, true) || dfs(row, col + 1, true) || dfs(row + 1, col + 1, true));
}

int main() {
    int t;
    scanf("%d", &t);

    while (t--) {
        int startingRow;
        scanf("%d %d", &n, &startingRow);

        for (int i = 0; i < 3; ++i) {
            scanf("%s", field[i]);
            field[i][n] = field[i][n + 1] = '.';
            field[i][n + 2] = 0;
            if (field[i][0] == 's') {
                startingRow = i;
            }
        }
        
        puts(dfs(startingRow, 0, false) ? "YES" : "NO");
    }
    return 0;
}/*1698306527.8952184*/