Create Merge Sort.py

Merge Sort

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+// Merge two subarrays L and M into arr
+void merge(int arr[], int p, int q, int r) {
+
+    // Create L ← A[p..q] and M ← A[q+1..r]
+    int n1 = q - p + 1;
+    int n2 = r - q;
+
+    int L[n1], M[n2];
+
+    for (int i = 0; i < n1; i++)
+        L[i] = arr[p + i];
+    for (int j = 0; j < n2; j++)
+        M[j] = arr[q + 1 + j];
+
+        // Maintain current index of sub-arrays and main array
+    int i, j, k;
+    i = 0;
+    j = 0;
+    k = p;
+
+    // Until we reach either end of either L or M, pick larger among
+    // elements L and M and place them in the correct position at A[p..r]
+    while (i < n1 && j < n2) {
+        if (L[i] <= M[j]) {
+            arr[k] = L[i];
+            i++;
+        } else {
+            arr[k] = M[j];
+            j++;
+        }
+        k++;
+    }
+    // When we run out of elements in either L or M,
+    // pick up the remaining elements and put in A[p..r]
+    while (i < n1) {
+        arr[k] = L[i];
+        i++;
+        k++;
+    }

MergeSort.py

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+# MergeSort in Python
+
+
+def mergeSort(array):
+    if len(array) > 1:
+
+        #  r is the point where the array is divided into two subarrays
+        r = len(array)//2
+        L = array[:r]
+        M = array[r:]
+
+        # Sort the two halves
+        mergeSort(L)
+        mergeSort(M)
+
+        i = j = k = 0
+
+        # Until we reach either end of either L or M, pick larger among
+        # elements L and M and place them in the correct position at A[p..r]
+        while i < len(L) and j < len(M):
+            if L[i] < M[j]:
+                array[k] = L[i]
+                i += 1
+            else:
+                array[k] = M[j]
+                j += 1
+            k += 1
+
+        # When we run out of elements in either L or M,
+        # pick up the remaining elements and put in A[p..r]
+        while i < len(L):
+            array[k] = L[i]
+            i += 1
+            k += 1
+
+        while j < len(M):
+            array[k] = M[j]
+            j += 1
+            k += 1
+
+
+# Print the array
+def printList(array):
+    for i in range(len(array)):
+        print(array[i], end=" ")
+    print()
+
+
+# Driver program
+if __name__ == '__main__':
+    array = [6, 5, 12, 10, 9, 1]
+
+    mergeSort(array)
+
+    print("Sorted array is: ")
+    printList(array)

SelectionSort.py

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+# Selection sort in Python
+
+
+def selectionSort(array, size):
+
+    for step in range(size):
+        min_idx = step
+
+        for i in range(step + 1, size):
+
+            # to sort in descending order, change > to < in this line
+            # select the minimum element in each loop
+            if array[i] < array[min_idx]:
+                min_idx = i
+
+        # put min at the correct position
+        (array[step], array[min_idx]) = (array[min_idx], array[step])
+
+
+data = [-2, 45, 0, 11, -9]
+size = len(data)
+selectionSort(data, size)
+print('Sorted Array in Ascending Order:')
+print(data)