Merge branch 'master' into master

README.md

@@ -68,5 +68,3 @@ Here are some common algorithms that can be applied to almost all data problems:
   - [Merge Sort](https://github.com/TheAlgorithms/R/blob/master/sorting/Merge%20sort.R)
   - [Radix Sort](https://github.com/TheAlgorithms/R/blob/master/sorting/Radix%20sort.R)
   - [Selection Sort](https://github.com/TheAlgorithms/R/blob/master/sorting/SelectionSort.R)
-  - [Quick Sort](https://github.com/TheAlgorithms/R/blob/master/sorting/Quick%20sort.R)  
-

sorting/Heap sort.R

@@ -0,0 +1,63 @@
+# Heap sort in R:
+
+build.heap <- function(elements.vec) {
+  l = length(elements.vec)
+  heap = elements.vec
+  for (i in l:1) {
+    heap = modify.heap(heap, i)
+  }
+  return(heap)
+}
+
+is.heap <- function(heap, rootIndex) {
+  i = rootIndex
+  res = T
+  while(2 * i <= length(heap) & res) {
+    child = c(heap[2 * i], heap[2 * i + 1])
+    child = child[!is.na(child)]
+    result.bool = all(heap[i] <= child)
+    i = i + 1
+  }
+  return(result.bool)
+}
+
+modify.heap <- function(heap, rootIndex) {
+  l = length(heap)
+  flag = 1  
+  while (rootIndex * 2 <= l && flag == 1) {
+    leftIndex = rootIndex * 2
+    rightIndex = rootIndex * 2 + 1
+    flag = 0
+    child = c(heap[leftIndex], heap[rightIndex])
+    child = child[!is.na(child)]
+    minIndex = which.min(child)
+    if (heap[rootIndex] > child[minIndex]) {
+      flag = 1
+      heapIndex = c(leftIndex, rightIndex)[minIndex]
+      temp = heap[heapIndex]
+      heap[heapIndex] = heap[rootIndex]
+      heap[rootIndex] = temp
+      rootIndex = heapIndex
+    }
+  }
+  return(heap)
+}
+
+heap.sort <- function(heap) {
+  sorted.elements = NULL
+  l = length(heap)
+  while(l > 0)
+  {
+    sorted.elements = c(sorted.elements, heap[1])
+    l = length(heap)
+    heap[1] = heap[l]
+    heap = heap[1:(l - 1)]
+    heap = modify.heap(heap, rootIndex = 1)
+    l = l - 1
+  }
+  return(sorted.elements)
+}
+
+# Example:
+# heap.sort(build.heap(c(5, 2, 3, 1, 4))) 
+# [1] 1 2 3 4 5