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36 lines
931 B
36 lines
931 B
7 years ago
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function graphTopoSort(numberNodes, edges) {
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const nodes = new Map();
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const order = [];
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const queue = [];
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for (let i = 0; i < numberNodes; i++) {
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nodes.set(i, { in: 0, out: new Set() });
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}
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edges.forEach(edge => {
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const [node_id, pre_id] = edge;
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nodes.get(node_id).in += 1;
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nodes.get(pre_id).out.add(node_id);
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});
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for (let [node_id, value] of nodes.entries()) {
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if (value.in === 0) {
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queue.push(node_id);
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}
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}
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while (queue.length) {
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const node_id = queue.shift();
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for (let outgoing_id of nodes.get(node_id).out) {
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nodes.get(outgoing_id).in -= 1;
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if (nodes.get(outgoing_id).in === 0) {
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queue.push(outgoing_id);
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}
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}
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order.push(node_id);
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}
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return order.length == numberNodes ? order : [];
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}
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console.log(graphTopoSort(3, [[0, 1], [0, 2]]))
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