const graph = {

  a: { b: 5, c: 2 },

  b: { a: 5, c: 7, d: 8 },

  c: { a: 2, b: 7, d: 4, e: 8 },

  d: { b: 8, c: 4, e: 6, f: 4 },

  e: { c: 8, d: 6, f: 3 },

  f: { e: 3, d: 4 },

};

​

const printTable = (table) => {

  return Object.keys(table)

    .map((vertex) => {

      var { vertex: from, cost } = table[vertex];

      return `${vertex}: ${cost} via ${from}`;

    })

    .join("\n");

};

​

const tracePath = (table, start, end) => {

  var path = [];

  var next = end;

  while (true) {

    path.unshift(next);

    if (next === start) {

      break;

    }

    next = table[next].vertex;

  }

​