insertionSort.py

Python/sorting_Algorithms/Insertion_Sort.py

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+def insertionSort(list):
+    # all the values after the first
+    index_length = range(1, len(list))
+    # to do an operation on all these values
+    # for all the value is the index_length value,
+    for i in index_length:
+    # we want to sort those values
+        sort = list[i]
+        # while the item to the left is greater than the item
+        # to the right
+        # notice that we also have to write i > 0 bc python allows
+        # for negative indexing
+        while list[i-1] > sort and i > 0:
+            # swap
+            list[i], list[i-1] = list[i-1], list[i]
+            # to continue doing comparisons down the list,
+            # look at the next item
+            i = i - 1
+
+    return list
+
+print(insertionSort([7, 3, 4, 1, 9]))
+
+'''
+THIS IS HOW IT WORKS
+# Mark the first element, 10, as sorted
+[10, 3, 2, 6]
+# Look at next element, 3, 3 < 10
+[10, 3, 2, 6]
+# Extract 3 and move it before 10, mark first element, 3 as sorted
+[3, 10, 2, 6]
+# Look at the next unsorted element, 2, 2 < 10, 2 < 3
+[3, 10, 2, 6]
+# Extract 2 and move it before 3, mark first element, 2, as sorted
+[2, 3, 10, 6]
+# Look at the next unsorted element, 6, 6 < 10, 6 > 3
+[2, 3, 10, 6]
+# Extract 6 and move it before 10
+[2, 3, 6, 10]
+'''