feat: prims algorithm

src/__tests__/ArrayList.ts

@@ -1,10 +1,7 @@
 import ArrayList from "@code/ArrayList";
 import { test_list } from "./ListTest";
 
-test("array-list", function() {
+test("array-list", function () {
     const list = new ArrayList<number>(3);
     test_list(list);
 });
-
-
-

src/__tests__/DijkstraList.ts

@@ -1,6 +1,6 @@
-import dijkstra_list from "@code/DijkstraList"
+import dijkstra_list from "@code/DijkstraList";
 
-test("dijkstra via adj list", function() {
+test("dijkstra via adj list", function () {
     const list: WeightedAdjacencyList = [];
 
     //      (1) --- (4) ---- (5)
@@ -8,23 +8,41 @@ test("dijkstra via adj list", function() {
     // (0)   | ------|------- |
     //    \  |/      |        |
     //      (1) --- (4) ---- (5)
-    list[0] = [{to: 1, weight: 3}, {to: 2, weight: 1}];
-    list[1] = [{to: 0, weight: 3}, {to: 2, weight: 4}, {to: 4, weight: 1}];
-    list[2] = [{to: 1, weight: 4}, {to: 3, weight: 7}, {to: 0, weight: 1}];
-    list[3] = [{to: 2, weight: 7}, {to: 4, weight: 5}, {to: 6, weight: 1}];
-    list[4] = [{to: 1, weight: 1}, {to: 3, weight: 5}, {to: 5, weight: 2}];
-    list[5] = [{to: 6, weight: 1}, {to: 4, weight: 2}];
-    list[6] = [{to: 3, weight: 1}, {to: 5, weight: 1}];
+    list[0] = [
+        { to: 1, weight: 3 },
+        { to: 2, weight: 1 },
+    ];
+    list[1] = [
+        { to: 0, weight: 3 },
+        { to: 2, weight: 4 },
+        { to: 4, weight: 1 },
+    ];
+    list[2] = [
+        { to: 1, weight: 4 },
+        { to: 3, weight: 7 },
+        { to: 0, weight: 1 },
+    ];
+    list[3] = [
+        { to: 2, weight: 7 },
+        { to: 4, weight: 5 },
+        { to: 6, weight: 1 },
+    ];
+    list[4] = [
+        { to: 1, weight: 1 },
+        { to: 3, weight: 5 },
+        { to: 5, weight: 2 },
+    ];
+    list[5] = [
+        { to: 6, weight: 1 },
+        { to: 4, weight: 2 },
+    ];
+    list[6] = [
+        { to: 3, weight: 1 },
+        { to: 5, weight: 1 },
+    ];
 
     /// waht?
     // what..
     // what...
-    expect(dijkstra_list(0, 6, list)).toEqual([
-        0,
-        1,
-        4,
-        5,
-        6,
-    ]);
+    expect(dijkstra_list(0, 6, list)).toEqual([0, 1, 4, 5, 6]);
 });
-

src/__tests__/DoublyLinkedList.ts

@@ -1,10 +1,7 @@
 import LinkedList from "@code/DoublyLinkedList";
 import { test_list } from "./ListTest";
 
-test("DoublyLinkedList", function() {
+test("DoublyLinkedList", function () {
     const list = new LinkedList<number>(3);
     test_list(list);
 });
-
-
-

src/__tests__/InsertionSort.ts

@@ -1,10 +1,9 @@
 import insertion_sort from "@code/InsertionSort";
 
-test("insertion-sort", function() {
+test("insertion-sort", function () {
     const arr = [9, 3, 7, 4, 69, 420, 42];
-    debugger
+    debugger;
     // where is my debugger
     insertion_sort(arr);
     expect(arr).toEqual([3, 4, 7, 9, 42, 69, 420]);
 });
-

src/__tests__/ListTest.ts

@@ -13,5 +13,4 @@ export function test_list(list: List<number>): void {
     expect(list.removeAt(0)).toEqual(5);
     expect(list.removeAt(0)).toEqual(11);
     expect(list.length).toEqual(0);
-
 }

src/__tests__/MergeSort.ts

@@ -1,9 +1,7 @@
 import merge_sort from "@code/MergeSort";
 
-test("merge-sort", function() {
+test("merge-sort", function () {
     const arr = [9, 3, 7, 4, 69, 420, 42];
     merge_sort(arr);
     expect(arr).toEqual([3, 4, 7, 9, 42, 69, 420]);
 });
-
-

src/__tests__/PrimsAlgorithm.ts

@@ -0,0 +1,69 @@
+import prims from "@code/PrimsAlgorithm";
+
+test("PrimsAlgorithm", function () {
+    const list: WeightedAdjacencyList = [];
+
+    //      (1) --- (4) ---- (5)
+    //    /  |       |       /|
+    // (0)   | ------|------- |
+    //    \  |/      |        |
+    //      (1) --- (4) ---- (5)
+    list[0] = [
+        { to: 1, weight: 3 },
+        { to: 2, weight: 1 },
+    ];
+    list[1] = [
+        { to: 0, weight: 3 },
+        { to: 2, weight: 4 },
+        { to: 4, weight: 1 },
+    ];
+    list[2] = [
+        { to: 1, weight: 4 },
+        { to: 3, weight: 7 },
+        { to: 0, weight: 1 },
+    ];
+    list[3] = [
+        { to: 2, weight: 7 },
+        { to: 4, weight: 5 },
+        { to: 6, weight: 1 },
+    ];
+    list[4] = [
+        { to: 1, weight: 1 },
+        { to: 3, weight: 5 },
+        { to: 5, weight: 2 },
+    ];
+    list[5] = [
+        { to: 6, weight: 1 },
+        { to: 4, weight: 2 },
+    ];
+    list[6] = [
+        { to: 3, weight: 1 },
+        { to: 5, weight: 1 },
+    ];
+
+    // there is only one right answer for this graph
+    expect(prims(list)).toEqual([
+        [
+            { to: 2, weight: 1 },
+            { to: 1, weight: 3 },
+        ],
+        [
+            { to: 0, weight: 3 },
+            { to: 4, weight: 1 },
+        ],
+        [{ to: 0, weight: 1 }],
+        [{ to: 6, weight: 1 }],
+        [
+            { to: 1, weight: 1 },
+            { to: 5, weight: 2 },
+        ],
+        [
+            { to: 4, weight: 2 },
+            { to: 6, weight: 1 },
+        ],
+        [
+            { to: 5, weight: 1 },
+            { to: 3, weight: 1 },
+        ],
+    ]);
+});

src/__tests__/Queue.ts

@@ -1,6 +1,6 @@
 import Queue from "@code/Queue";
 
-test("queue", function() {
+test("queue", function () {
     const list = new Queue<number>();
 
     list.enqueue(5);
@@ -11,7 +11,7 @@ test("queue", function() {
     expect(list.length).toEqual(2);
 
     // this must be wrong..?
-    debugger
+    debugger;
 
     // i hate using debuggers
     list.enqueue(11);
@@ -29,5 +29,3 @@ test("queue", function() {
     expect(list.peek()).toEqual(69);
     expect(list.length).toEqual(1);
 });
-
-

src/__tests__/QuickSort.ts

@@ -1,12 +1,9 @@
 import quick_sort from "@code/QuickSort";
 
-test("quick-sort", function() {
+test("quick-sort", function () {
     const arr = [9, 3, 7, 4, 69, 420, 42];
 
     debugger;
     quick_sort(arr);
     expect(arr).toEqual([3, 4, 7, 9, 42, 69, 420]);
 });
-
-
-

src/__tests__/SinglyLinkedList.ts

@@ -1,9 +1,7 @@
 import LinkedList from "@code/SingleLinkedList";
 import { test_list } from "./ListTest";
 
-test("linked-list", function() {
+test("linked-list", function () {
     const list = new LinkedList<number>(3);
     test_list(list);
 });
-
-

src/__tests__/Stack.ts

@@ -1,6 +1,6 @@
 import Stack from "@code/Stack";
 
-test("stack", function() {
+test("stack", function () {
     const list = new Stack<number>();
 
     list.push(5);
@@ -25,6 +25,3 @@ test("stack", function() {
 
     //yayaya
 });
-
-
-

src/global.d.ts

@@ -6,7 +6,8 @@ declare interface List<T> {
     add(item: T): void;
 }
 
-declare type GraphEdge = {to: number, weight: number};
+declare type CompleteGraphEdge = { from: number; to: number; weight: number };
+declare type GraphEdge = { to: number; weight: number };
 declare type WeightedAdjacencyList = GraphEdge[][];
 declare type WeightedAdjacencyMatrix = number[][]; // A number means weight
 
@@ -17,9 +18,9 @@ declare type BinaryNode<T> = {
     value: T;
     left: BinaryNode<T>;
     right: BinaryNode<T>;
-}
+};
 
 declare type GeneralNode<T> = {
     value: T;
-    children: GeneralNode<T>[]
-}
+    children: GeneralNode<T>[];
+};

src/graph.ts

@@ -0,0 +1,13 @@
+export function add_node_list(
+    list: WeightedAdjacencyList,
+    from: number,
+    to: number,
+    weight: number,
+): void {
+    let l = list[from];
+    if (!l) {
+        l = list[from] = [];
+    }
+
+    l.push({ to, weight });
+}