java回溯法矩陣中的路徑

package algorithmBasic;

/**
 * @author kegekeqi
 * @version 1.0
 * @date 2021-12-12 22:24
 */
public class HuiSuo {
  public boolean hasPath(char[] matrix, int rows, int cols, char[] str) {
    if (null == matrix || rows < 1 || cols < 1 || str == null) {
      return false;
    }
    boolean[][] visited = new boolean[rows][cols];
    for (int row = 0; row < rows; row++) {
      for (int col = 0; col < cols; col++) {
        if (hasPath(matrix, rows, cols, row, col, str, 0, visited)) {
          return true;
        }
      }
    }
    return false;
  }

  private boolean hasPath(char[] matrix, int rows, int cols, int row, int col,
              char[] str, int index, boolean[][] visited) {
    if (index == str.length) {
      return  true;
    }

    if (row >= 0 && row < rows && col >= 0 && col < cols && !visited[row][col]
        && matrix[cols * row + col] == str[index]) {
      visited[row][col] = true;
      if (hasPath(matrix, rows, cols, row - 1, col, str, index + 1, visited)
          || hasPath(matrix, rows, cols, row + 1, col, str, index + 1, visited)
          || hasPath(matrix, rows, cols, row, col - 1, str, index + 1, visited)
          || hasPath(matrix, rows, cols, row, col + 1, str, index + 1, visited)) {
        return true;
      }
      visited[row][col] = false;
    }
    return false;

  }
}