A newly-discovered planet has a few continents with one or more countries in each continent. Countries within a continent have land borders with at least another country in the same continent, and no two countries from different continents have a land border. Given a matrix of land borders between countries, we would like to calculate how many continents there are.
The borders data for
ncountries is an
n X nmatrix, where a value of
1at i-th row and j-th column means a direct land border between i-th and j-th countries, and
0means no border. The matrix is symmetric, and no country has a border with itself.
Given the borders matrix, return the number of continents.
continents([ [ 0, 1, 0 ], [ 1, 0, 0 ], [ 0, 0, 0 ] ]);