From 9f0c186d538bee9802c83ed29688f7db31d4b8a5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mateusz=20Szu=C5=82a?= <mateusz.szulaa@gmail.com>
Date: Wed, 3 Jan 2024 17:41:39 +0100
Subject: [PATCH] Added Counting Sort & Radix Sort

---
 README.md                                |  2 +
 src/lib/sort-algorithms/algorithms.ts    | 10 ++++
 src/lib/sort-algorithms/counting-sort.ts | 34 ++++++++++++
 src/lib/sort-algorithms/radix-sort.ts    | 67 ++++++++++++++++++++++++
 4 files changed, 113 insertions(+)
 create mode 100644 src/lib/sort-algorithms/counting-sort.ts
 create mode 100644 src/lib/sort-algorithms/radix-sort.ts

diff --git a/README.md b/README.md
index 88d6396..ea3259c 100644
--- a/README.md
+++ b/README.md
@@ -25,6 +25,8 @@ https://github.com/mszula/visual-sorting/assets/17621834/3077ad21-ed6e-432c-ae51
 - Quick Sort
 - Shell Sort
 - Merge Sort
+- Counting Sort
+- Radix Sort
 
 ## 🙌 Contribution
 
diff --git a/src/lib/sort-algorithms/algorithms.ts b/src/lib/sort-algorithms/algorithms.ts
index 7440d2d..a12eab6 100644
--- a/src/lib/sort-algorithms/algorithms.ts
+++ b/src/lib/sort-algorithms/algorithms.ts
@@ -1,7 +1,9 @@
 import { bubleSort } from "./buble-sort";
+import { countingSort } from "./counting-sort";
 import { insertionSort } from "./insertion-sort";
 import { mergeSort } from "./merge-sort";
 import { quickSort } from "./quick-sort";
+import { radixSort } from "./radix-sort";
 import { selectionSort } from "./selection-sort";
 import { shellSort } from "./shell-sort";
 import type { AlgorithmDefinition } from "./types";
@@ -31,4 +33,12 @@ export const algorithms: AlgorithmDefinition[] = [
     name: "Merge Sort",
     function: mergeSort,
   },
+  {
+    name: "Counting Sort",
+    function: countingSort,
+  },
+  {
+    name: "Radix Sort",
+    function: radixSort,
+  },
 ];
diff --git a/src/lib/sort-algorithms/counting-sort.ts b/src/lib/sort-algorithms/counting-sort.ts
new file mode 100644
index 0000000..0431a5f
--- /dev/null
+++ b/src/lib/sort-algorithms/counting-sort.ts
@@ -0,0 +1,34 @@
+import type { SortingGenerator } from "./types";
+
+export const countingSort = function* (arr: number[]): SortingGenerator {
+  let j = 0,
+    max = arr[0],
+    count = [];
+
+  for (let i = 0; i < arr.length; i++) {
+    yield { accesing: [i], sound: i };
+    if (arr[i] > max) {
+      max = arr[i];
+    }
+  }
+
+  for (let i = 0; i <= max; i++) {
+    yield { accesing: [i], sound: i };
+    count[i] = 0;
+  }
+
+  for (let i = 0; i < arr.length; i++) {
+    yield { accesing: [i], sound: i };
+    count[arr[i]] += 1;
+  }
+
+  console.log(count);
+  for (let i = 0; i <= max; i++) {
+    while (count[i] > 0) {
+      yield { accesing: [j], sound: j };
+      arr[j] = i;
+      j++;
+      count[i]--;
+    }
+  }
+};
diff --git a/src/lib/sort-algorithms/radix-sort.ts b/src/lib/sort-algorithms/radix-sort.ts
new file mode 100644
index 0000000..dc32205
--- /dev/null
+++ b/src/lib/sort-algorithms/radix-sort.ts
@@ -0,0 +1,67 @@
+import type { SortingGenerator } from "./types";
+
+const getMax = function* (arr: number[], n: number) {
+  let mx = arr[0];
+  for (let i = 1; i < n; i++) {
+    yield { accesing: [i], sound: i };
+    if (arr[i] > mx) {
+      mx = arr[i];
+    }
+  }
+  return mx;
+};
+
+const countSort = function* (
+  arr: number[],
+  n: number,
+  exp: number
+): SortingGenerator {
+  const output = new Array(n); // output array
+  const count = new Array(10);
+
+  let i;
+  for (let i = 0; i < 10; i++) count[i] = 0;
+
+  // Store count of occurrences in count[]
+  for (i = 0; i < n; i++) {
+    let x = Math.floor(arr[i] / exp) % 10;
+    count[x]++;
+    yield { accesing: [i], sound: i };
+  }
+
+  // Change count[i] so that count[i] now contains
+  // actual position of this digit in output[]
+  for (i = 1; i < 10; i++) count[i] += count[i - 1];
+
+  // Build the output array
+  for (i = n - 1; i >= 0; i--) {
+    let x = Math.floor(arr[i] / exp) % 10;
+    output[count[x] - 1] = arr[i];
+    count[x]--;
+    yield { accesing: [i], sound: i };
+  }
+
+  // Copy the output array to arr[], so that arr[] now
+  // contains sorted numbers according to current digit
+  for (i = 0; i < n; i++) {
+    arr[i] = output[i];
+    yield { accesing: [i], sound: i };
+  }
+};
+
+// The main function to that sorts arr[] of size n using
+// Radix Sort
+export const radixSort = function* (arr: number[]): SortingGenerator {
+  const len = arr.length;
+  // Find the maximum number to know number of digits
+  const m = yield* getMax(arr, len);
+
+  // Do counting sort for every digit. Note that
+  // instead of passing digit number, exp is passed.
+  // exp is 10^i where i is current digit number
+  for (let exp = 1; Math.floor(m / exp) > 0; exp *= 10) {
+    yield { accesing: [] };
+    yield* countSort(arr, len, exp);
+    yield { accesing: [] };
+  }
+};