Added Prims Algorithm [JavaScript]

README.md

@@ -39,7 +39,7 @@ Community (college) maintained list of Algorithms and Data Structures implementa
 | [Modular Exponential](http://www.geeksforgeeks.org/modular-exponentiation-power-in-modular-arithmetic/) | [:white_check_mark:](modular_exponential/modular_exponential.c) | | [:white_check_mark:](modular_exponential/ModularExponential.java) | [:white_check_mark:](modular_exponential/modular_exponential.py) | [:white_check_mark:](modular_exponential/modular_exponential.go) | [:white_check_mark:](modular_exponential/modularExponential.js) | |
 | [N-Queen Problem](https://en.wikipedia.org/wiki/Eight_queens_puzzle) | | [:white_check_mark:](n_queen_problem/NQueenProblem.cpp) | [:white_check_mark:](n_queen_problem/NQueenProblem.java) | [:white_check_mark:](n_queen_problem/n_queen_problem.py) | | | |
 | [Prime Factor](https://en.wikipedia.org/wiki/Prime_factor) | [:white_check_mark:](prime_factor/prime_factor.c) | | [:white_check_mark:](prime_factor/PrimeFactor.java) | [:white_check_mark:](prime_factor/prime_factor.py) | [:white_check_mark:](prime_factor/prime_factor.go) | [:white_check_mark:](prime_factor/primeFactor.js) | |
-| [Prims](https://en.wikipedia.org/wiki/Prim%27s_algorithm) | [:white_check_mark:](prims/prims.c) | | [:white_check_mark:](prims/Prims.java) | | | | |
+| [Prims](https://en.wikipedia.org/wiki/Prim%27s_algorithm) | [:white_check_mark:](prims/prims.c) | | [:white_check_mark:](prims/Prims.java) | | | [:white_check_mark:](prims/prims.js) | |
 | [Quick Select](https://en.wikipedia.org/wiki/Quickselect) | [:white_check_mark:](quick_select/quick_select.c) | | [:white_check_mark:](quick_select/QuickSelect.java) | [:white_check_mark:](quick_select/quick_select.py) | | | |
 | [Quicksort](https://en.wikipedia.org/wiki/Quicksort) | [:white_check_mark:](quick_sort/quicksort.c) | | [:white_check_mark:](quick_sort/QuickSort.java) | [:white_check_mark:](quick_sort/quick_sort.py) | [:white_check_mark:](quick_sort/quick_sort.go) | [:white_check_mark:](quick_sort/quickSort.js) | [:white_check_mark:](quick_sort/QuickSort.cs) |
 | [Radix Sort](http://www.geeksforgeeks.org/radix-sort/) | | | | [:white_check_mark:](radix_sort/radix_sort.py) | | | |

prims/prims.js

@@ -0,0 +1,80 @@
+function minKey (key, visited) {
+	let min = Number.MAX_VALUE;
+	let minIdx = -1;
+	let length = key.length;
+
+	for (let i = 0; i < length; i++) {
+		if (!visited[i] && key[i] < min) {
+			min = key[i];
+			minIdx = i;
+		}
+	}
+
+	return minIdx;
+}
+
+function generate (graph) {
+	/*
+	* Get the parent nodes in the MST
+	* :param graph: array which represents the graph
+	* :return: returns array of parent nodes
+	*/
+	let length = graph.length;
+
+	// stores the parent of each vertex
+	let parent = [];
+	// key value of each vertex
+	let key = [];
+	// flag for included in the MST
+	let mstSet = [];
+
+	// initialize arguments
+	for (let i = 0; i < length; i++) {
+		mstSet[i] = false;
+		key[i] = Number.MAX_VALUE;
+	}
+
+	// starting from the first vertex
+	// the first vertex is the root, so it doesn't have any parent
+	key[0] = 0;
+	parent[0] = -1;
+
+	for (let i = 0; i < length - 1; i++) {
+		// minimum key from given vertices
+		let u = minKey(key, mstSet);
+		mstSet[u] = true;
+
+		// updating the neighbours key
+		for (let j = 0; j < length; j++) {
+			if (graph[u][j] !== 0 && !mstSet[j] && graph[u][j] < key[j]) {
+				parent[j] = u;
+				key[j] = graph[u][j];
+			}
+		}
+	}
+
+	return parent;
+}
+
+function main () {
+	// given graph
+	let graph = [
+		[0, 2, 0, 6, 0],
+		[2, 0, 3, 8, 5],
+		[0, 3, 0, 0, 7],
+		[6, 8, 0, 0, 9],
+		[0, 5, 7, 9, 0]
+	];
+
+	// get the parent nodes of all the vertices
+	let parent = generate(graph);
+	let length = graph.length;
+
+	// print the MST
+	console.log('Edge : Weight');
+	for (let i = 1; i < length; i++) {
+		console.log(parent[i] + ' - ' + i + ' : ' + graph[i][parent[i]]);
+	}
+}
+
+main();