precedence-diagram-method/ignoreCoverage/DetectLoopInGraph.js

An API to calculate the precedence diagram method

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
class DetectLoopInGraph {
    constructor(graphJSON) {
        let graph = JSON.parse(JSON.stringify(graphJSON));
        this.graph = graph;
    }
    // Returns true if the graph contains a
    // cycle, else false.
    // This function is a variation of DFS() in
    // https://www.geeksforgeeks.org/archives/18212
    isCyclic() {
        // Mark all the vertices as not visited and
        // not part of recursion stack
        let visited = [];
        let recStack = [];
        let nodes = Object.keys(this.graph);
        for (let node of nodes) {
            visited[node] = false;
            recStack[node] = false;
        }
        // Call the recursive helper function to
        // detect cycle in different DFS trees
        for (let node of nodes)
            if (this.isCyclicUtil(node, visited, recStack))
                return true;
        return false;
    }
    // This function is a variation of DFSUtil() in
    // https://www.geeksforgeeks.org/archives/18212
    isCyclicUtil(label, visited, recStack) {
        // Mark the current node as visited and
        // part of recursion stack
        if (recStack[label])
            return true;
        if (visited[label])
            return false;
        visited[label] = true;
        recStack[label] = true;
        let children = this.graph[label].children;
        for (let child of children)
            if (this.isCyclicUtil(child, visited, recStack))
                return true;
        recStack[label] = false;
        return false;
    }
}
exports.default = DetectLoopInGraph;