File size: 3,711 Bytes
bc20498 |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 |
import * as is from '../../is';
import { defaults } from '../../util';
const hierholzerDefaults = defaults({
root: undefined,
directed: false
});
let elesfn = ({
hierholzer: function( options ){
if (!is.plainObject(options)) {
let args = arguments;
options = { root: args[0], directed: args[1] };
}
let { root, directed } = hierholzerDefaults(options);
let eles = this;
let dflag = false;
let oddIn;
let oddOut;
let startVertex;
if (root) startVertex = is.string(root) ? this.filter(root)[0].id() : root[0].id();
let nodes = {};
let edges = {};
if (directed) {
eles.forEach(function(ele){
let id = ele.id();
if(ele.isNode()) {
let ind = ele.indegree(true);
let outd = ele.outdegree(true);
let d1 = ind - outd;
let d2 = outd - ind;
if (d1 == 1) {
if (oddIn) dflag = true;
else oddIn = id;
} else if (d2 == 1) {
if (oddOut) dflag = true;
else oddOut = id;
} else if ((d2 > 1) || (d1 > 1)) {
dflag = true;
}
nodes[id] = [];
ele.outgoers().forEach(e => {
if (e.isEdge()) nodes[id].push(e.id());
});
} else {
edges[id] = [undefined, ele.target().id()];
}
});
} else {
eles.forEach(function(ele){
let id = ele.id();
if(ele.isNode()) {
let d = ele.degree(true);
if (d%2) {
if (!oddIn) oddIn = id;
else if (!oddOut) oddOut = id;
else dflag = true;
}
nodes[id] = [];
ele.connectedEdges().forEach(e => nodes[id].push(e.id()));
} else {
edges[id] = [ele.source().id(), ele.target().id()];
}
});
}
let result = {
found: false,
trail: undefined
};
if (dflag) return result;
else if (oddOut && oddIn) {
if (directed) {
if (startVertex && (oddOut != startVertex)) {
return result;
}
startVertex = oddOut;
} else {
if (startVertex && (oddOut != startVertex) && (oddIn != startVertex)) {
return result;
} else if (!startVertex) {
startVertex = oddOut;
}
}
} else {
if (!startVertex) startVertex = eles[0].id();
}
const walk = (v) => {
let currentNode = v;
let subtour = [v];
let adj, adjTail, adjHead;
while (nodes[currentNode].length) {
adj = nodes[currentNode].shift();
adjTail = edges[adj][0];
adjHead = edges[adj][1];
if (currentNode != adjHead) {
nodes[adjHead] = nodes[adjHead].filter(e => e != adj);
currentNode = adjHead;
} else if (!directed && (currentNode != adjTail)) {
nodes[adjTail] = nodes[adjTail].filter(e => e != adj);
currentNode = adjTail;
}
subtour.unshift(adj);
subtour.unshift(currentNode);
}
return subtour;
};
let trail = [];
let subtour = [];
subtour = walk(startVertex);
while (subtour.length != 1) {
if (nodes[subtour[0]].length == 0) {
trail.unshift(eles.getElementById(subtour.shift()));
trail.unshift(eles.getElementById(subtour.shift()));
} else {
subtour = walk(subtour.shift()).concat(subtour);
}
}
trail.unshift(eles.getElementById(subtour.shift())); // final node
for (let d in nodes) {
if (nodes[d].length) {
return result;
}
}
result.found = true;
result.trail = this.spawn( trail, true );
return result;
},
});
export default elesfn;
|