Challenge to get nb of islands present on a map.

islands.js

// Land is represented as #
// water is -
// Land that connected on at least one side with another land belongs to the same island.

// Get the count of islands.

const map1 = `
------
--###-
---##-
##----
-----#
`.trim(); // 3 islands

const map2 = `
##----
--###-
---##-
##----
--#-##
`.trim(); // 5 islands

const map3 = `
------
------
------
------
------
`.trim(); // 0 islands

function getIslandsCount(map) {
  const matrix = map.split("\n");
  let count = 0;
  const rows = matrix.map((row, i) => ({
    rowIndex: i,
    line: row.split("")
  }));

  rows.forEach(({ rowIndex, line }) => {
    line.forEach((el, elIndex) => {
      const beforeRowExist = rowIndex > 0;
      if (el === "#" && line[elIndex - 1] !== "#") {
        if (beforeRowExist) {
          if (rows[rowIndex - 1].line[elIndex] !== "#") {
            count++;
          }
        } else {
          count++;
        }
      }
    });
  });
  return count;
}

console.log(getIslandsCount(map3));