From 6584f8491b4f8fb6ad8e6a9278b80090d1218827 Mon Sep 17 00:00:00 2001
From: Koo Xin Tong <kooxintong0221@gmail.com>
Date: Mon, 8 Aug 2022 15:18:24 +0800
Subject: [PATCH] (C++) add bead sort into sorting algorithm
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The algorithm’s run–time complexity ranges from O(n) to O(S)
---
 .gitignore                                 |  9 ++++
 algorithms/CPlusPlus/README.md             |  1 +
 algorithms/CPlusPlus/Sorting/bead-sort.cpp | 56 ++++++++++++++++++++++
 3 files changed, 66 insertions(+)
 create mode 100644 algorithms/CPlusPlus/Sorting/bead-sort.cpp

diff --git a/.gitignore b/.gitignore
index c15b5c75..656b63b7 100644
--- a/.gitignore
+++ b/.gitignore
@@ -15,3 +15,12 @@ Thumbs.db
 
 # Visual Studio Code
 .vscode/
+.vs/DSA/v16/.suo
+.vs/DSA/v16/Browse.VC.db
+.vs/DSA/v16/Browse.VC.db-shm
+.vs/DSA/v16/Browse.VC.db-wal
+.vs/DSA/v16/Browse.VC.opendb
+.vs/ProjectSettings.json
+.vs/slnx.sqlite
+.vs/DSA/v16/ipch/AutoPCH/26ffe219c79f338e/BEAD-SORT.ipch
+.vs/VSWorkspaceState.json
diff --git a/algorithms/CPlusPlus/README.md b/algorithms/CPlusPlus/README.md
index c545fa88..83e30455 100644
--- a/algorithms/CPlusPlus/README.md
+++ b/algorithms/CPlusPlus/README.md
@@ -109,6 +109,7 @@
 - [Merge Sort](Sorting/merge-sort.cpp)
 - [Wave Sort](Sorting/wave-sort.cpp)
 - [Cycle Sort](Sorting/cycle-sort.cpp)
+- [Bead Sort](Sorting/bead-sort.cpp)
 
 ## Strings
 
diff --git a/algorithms/CPlusPlus/Sorting/bead-sort.cpp b/algorithms/CPlusPlus/Sorting/bead-sort.cpp
new file mode 100644
index 00000000..24dfa761
--- /dev/null
+++ b/algorithms/CPlusPlus/Sorting/bead-sort.cpp
@@ -0,0 +1,56 @@
+// C++ program to implement gravity/bead sort
+#include <cstdio>
+#include <cstring>
+
+#define BEAD(i, j) beads[i * max + j]
+
+// function to perform the above algorithm
+void beadSort(int* a, int len) {
+    // Find the maximum element
+    int max = a[0];
+    for (int i = 1; i < len; i++)
+        if (a[i] > max)
+            max = a[i];
+
+    // allocating memory
+    unsigned char* beads = new unsigned char[max * len];
+    memset(beads, 0, static_cast<size_t>(max) * len);
+
+    // mark the beads
+    for (int i = 0; i < len; i++)
+        for (int j = 0; j < a[i]; j++) BEAD(i, j) = 1;
+
+    for (int j = 0; j < max; j++) {
+        // count how many beads are on each post
+        int sum = 0;
+        for (int i = 0; i < len; i++) {
+            sum += BEAD(i, j);
+            BEAD(i, j) = 0;
+        }
+
+        // Move beads down
+        for (int i = len - sum; i < len; i++) BEAD(i, j) = 1;
+    }
+
+    // Put sorted values in array using beads
+    for (int i = 0; i < len; i++) {
+        int j;
+        for (j = 0; j < max && BEAD(i, j); j++) {
+        }
+
+        a[i] = j;
+    }
+    delete[] beads;
+}
+
+// driver function to test the algorithm
+int main() {
+    int a[] = { 5, 3, 1, 7, 4, 1, 1, 20 };
+    int len = sizeof(a) / sizeof(a[0]);
+
+    beadSort(a, len);
+
+    for (int i = 0; i < len; i++) printf("%d ", a[i]);
+
+    return 0;
+}
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