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| 1 | +def min_heapify(arr,n,i): |
| 2 | + """This function will perform max heapify on elements level-wise |
| 3 | + or wil choose largest among it's left,right child and itself. |
| 4 | + Parameters: |
| 5 | + arr: List of integers. |
| 6 | + n: Length of list arr. |
| 7 | + i: index of element |
| 8 | + Returns: |
| 9 | + None |
| 10 | + """ |
| 11 | + smallest = i |
| 12 | + left = 2*i + 1 |
| 13 | + right = 2*i + 2 |
| 14 | + |
| 15 | + if(left<n and arr[left]<arr[smallest]): |
| 16 | + smallest = left |
| 17 | + if(right<n and arr[right]<arr[smallest]): |
| 18 | + smallest = right |
| 19 | + |
| 20 | + if(i!=smallest): |
| 21 | + arr[i],arr[smallest] = arr[smallest],arr[i] |
| 22 | + |
| 23 | + min_heapify(arr,n,smallest) |
| 24 | + |
| 25 | + |
| 26 | +def max_heapify(arr,n,i): |
| 27 | + """This function will perform max heapify on elements level-wise |
| 28 | + or wil choose largest among it's left,right child and itself. |
| 29 | + Parameters: |
| 30 | + arr: List of integers. |
| 31 | + n: Length of list arr. |
| 32 | + i: index of element |
| 33 | + Returns: |
| 34 | + None |
| 35 | + """ |
| 36 | + largest = i |
| 37 | + left = 2*i + 1 |
| 38 | + right = 2*i + 2 |
| 39 | + |
| 40 | + if(left < n and arr[left] > arr[largest]): |
| 41 | + largest = left |
| 42 | + if(right < n and arr[right] > arr[largest]): |
| 43 | + largest = right |
| 44 | + if(i!=largest): |
| 45 | + arr[i],arr[largest] = arr[largest],arr[i] |
| 46 | + max_heapify(arr,n,largest) |
| 47 | + |
| 48 | + |
| 49 | +def min_build_heap(arr,n): |
| 50 | + """This function will build min heap. |
| 51 | + Parameters: |
| 52 | + arr: List of integers. |
| 53 | + n: Length of list arr. |
| 54 | + Returns: |
| 55 | + None |
| 56 | + """ |
| 57 | + for i in range(len(arr)//2): |
| 58 | + min_heapify(arr,n,i) |
| 59 | + |
| 60 | + |
| 61 | +def max_build_heap(arr,n): |
| 62 | + """This function will build max heap. |
| 63 | + Parameters: |
| 64 | + arr: List of integers. |
| 65 | + n: Length of list arr. |
| 66 | + """ |
| 67 | + for i in range(len(arr)//2): |
| 68 | + max_heapify(arr,n,i) |
| 69 | + |
| 70 | + |
| 71 | +def main(): |
| 72 | + arr = [8,2,5,6,9] |
| 73 | + n = len(arr) |
| 74 | + print("List Before min heapify =>",arr) |
| 75 | + min_build_heap(arr,n) |
| 76 | + print("List after min heapify=>",arr) |
| 77 | + arr = [8,2,5,6,9] |
| 78 | + print("List Before min heapify =>",arr) |
| 79 | + max_build_heap(arr,n) |
| 80 | + print("List after min heapify=>",arr) |
| 81 | + |
| 82 | +if __name__ == "__main__": |
| 83 | + main() |
| 84 | + |
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