getStructure.js

const blackCharacter = '#';

export function getStructure( matrix ) {
  const lineLength = matrix.length && matrix[0].length;
  const dictionary = [];
  for ( let i=0; i<matrix.length; i++) {
    for ( let j=0; j<lineLength; j++ ) {
      // Horizontal
      if ( j==0 || matrix[i][j-1] === blackCharacter && matrix[i][j] !== blackCharacter ) {
        let a=j;
        // Find last blackCharacter of the row
        for ( ; a<lineLength && matrix[i][a] !== blackCharacter; ) { a++; }
        const wordLength = a-j;
        if ( wordLength > 1 ) {
          dictionary.push({
            col : j,
            row : i,
            length : wordLength,
            horizontal : true
          });
        }
      }
      // Vertical
      if ( i==0 || matrix[i-1][j] === blackCharacter && matrix[i][j] !== blackCharacter ) {
        let a=i;
        // Find last blackCharacter of the col
        for ( ; a<lineLength && matrix[a][j] !== blackCharacter; ) { a++; }
        const wordLength = a-i;
        if ( wordLength > 1 ) {
          dictionary.push({
            col : j,
            row : i,
            length : wordLength,
            horizontal : false
          });
        }
      }
    }
  }
  return dictionary;
}