deploy: 57ea7b1f9d

heap_sort.cpp

@@ -0,0 +1,52 @@
+#include <algorithm>
+#include <iostream>
+
+void heapify(int *a, int i, int n) {
+    int largest = i;
+    const int l = 2 * i + 1;
+    const int r = 2 * i + 2;
+
+    if (l < n && a[l] > a[largest])
+        largest = l;
+
+    if (r < n && a[r] > a[largest])
+        largest = r;
+
+    if (largest != i) {
+        std::swap(a[i], a[largest]);
+        heapify(a, n, largest);
+    }
+}
+
+void heapsort(int *a, int n) {
+    for (int i = n - 1; i >= 0; --i) {
+        std::swap(a[0], a[i]);
+        heapify(a, 0, i);
+    }
+}
+
+void build_maxheap(int *a, int n) {
+    for (int i = n / 2 - 1; i >= 0; --i) {
+        heapify(a, i, n);
+    }
+}
+
+int main() {
+    int n;
+    std::cout << "Enter number of elements of array\n";
+    std::cin >> n;
+    int a[20];
+    for (int i = 0; i < n; ++i) {
+        std::cout << "Enter Element " << i << std::endl;
+        std::cin >> a[i];
+    }
+
+    build_maxheap(a, n);
+    heapsort(a, n);
+    std::cout << "Sorted Output\n";
+    for (int i = 0; i < n; ++i) {
+        std::cout << a[i] << std::endl;
+    }
+
+    std::getchar();
+}