'use strict';

const distinct = (dataset) => {

const keys = new Set();

return dataset.filter((record) => {

const cols = Object.keys(record).sort();

const key = cols.map((field) => record[field]).join('\x00');

const has = keys.has(key);

if (!has) keys.add(key);

return !has;

});

};

// Usage

const flights = [

{ from: 'Kiev', to: 'Rome' },

{ from: 'Kiev', to: 'Warsaw' },

{ from: 'Dublin', to: 'Riga' },

{ from: 'Riga', to: 'Dublin' },

{ from: 'Kiev', to: 'Rome' },

{ from: 'Cairo', to: 'Paris' },

];

console.dir({ flights });

const directions = distinct(flights);

console.dir({ directions });