// https://www.freecodecamp.org/learn/coding-interview-prep/data-structures/incidence-matrix

const row = [];
for (let i = 0; i < 4; i++) {
  row.push(0);
}
const incMatUndirected = [];
for (let i = 0; i < 5; i++) {
  incMatUndirected.push([...row]);
}
const edges = [
  [1, 2],
  [2, 3],
  [3, 5],
  [4, 2],
];
edges.forEach((e, i) => {
  incMatUndirected[e[0] - 1][i] = 1;
  incMatUndirected[e[1] - 1][i] = 1;
});

console.log(incMatUndirected);