Innovenergy_trunk/frontend/node_modules/graphlib/lib/alg/tarjan.js

48 lines
962 B
JavaScript
Raw Normal View History

var _ = require("../lodash");
module.exports = tarjan;
function tarjan(g) {
var index = 0;
var stack = [];
var visited = {}; // node id -> { onStack, lowlink, index }
var results = [];
function dfs(v) {
var entry = visited[v] = {
onStack: true,
lowlink: index,
index: index++
};
stack.push(v);
g.successors(v).forEach(function(w) {
if (!_.has(visited, w)) {
dfs(w);
entry.lowlink = Math.min(entry.lowlink, visited[w].lowlink);
} else if (visited[w].onStack) {
entry.lowlink = Math.min(entry.lowlink, visited[w].index);
}
});
if (entry.lowlink === entry.index) {
var cmpt = [];
var w;
do {
w = stack.pop();
visited[w].onStack = false;
cmpt.push(w);
} while (v !== w);
results.push(cmpt);
}
}
g.nodes().forEach(function(v) {
if (!_.has(visited, v)) {
dfs(v);
}
});
return results;
}