tech-interview-handbook/utilities/javascript/graphTopoSort.js

function graphTopoSort(numberNodes, edges) {
    const nodes = new Map();
    const order = [];
    const queue = [];
    for (let i = 0; i < numberNodes; i++) {
        nodes.set(i, { in: 0, out: new Set() });
    }

    edges.forEach(edge => {
        const [node_id, pre_id] = edge;
        nodes.get(node_id).in += 1;
        nodes.get(pre_id).out.add(node_id);
    });

    for (let [node_id, value] of nodes.entries()) {
        if (value.in === 0) {
            queue.push(node_id);
        }
    }

    while (queue.length) {
        const node_id = queue.shift();
        for (let outgoing_id of nodes.get(node_id).out) {
            nodes.get(outgoing_id).in -= 1;
            if (nodes.get(outgoing_id).in === 0) {
                queue.push(outgoing_id);
            }
        }
        order.push(node_id);
    }

    return order.length == numberNodes ? order : [];
}

console.log(graphTopoSort(3, [[0, 1], [0, 2]]));