hello-algo/en/codes/python/chapter_searching/binary_search_insertion.py
Yudong Jin 1c0f350ad6
translation: Add Python and Java code for EN version (#1345)
* Add the intial translation of code of all the languages

* test

* revert

* Remove

* Add Python and Java code for EN version
2024-05-06 05:21:51 +08:00

54 lines
1.9 KiB
Python

"""
File: binary_search_insertion.py
Created Time: 2023-08-04
Author: krahets (krahets@163.com)
"""
def binary_search_insertion_simple(nums: list[int], target: int) -> int:
"""Binary search for insertion point (no duplicate elements)"""
i, j = 0, len(nums) - 1 # Initialize double closed interval [0, n-1]
while i <= j:
m = (i + j) // 2 # Calculate midpoint index m
if nums[m] < target:
i = m + 1 # Target is in interval [m+1, j]
elif nums[m] > target:
j = m - 1 # Target is in interval [i, m-1]
else:
return m # Found target, return insertion point m
# Did not find target, return insertion point i
return i
def binary_search_insertion(nums: list[int], target: int) -> int:
"""Binary search for insertion point (with duplicate elements)"""
i, j = 0, len(nums) - 1 # Initialize double closed interval [0, n-1]
while i <= j:
m = (i + j) // 2 # Calculate midpoint index m
if nums[m] < target:
i = m + 1 # Target is in interval [m+1, j]
elif nums[m] > target:
j = m - 1 # Target is in interval [i, m-1]
else:
j = m - 1 # First element less than target is in interval [i, m-1]
# Return insertion point i
return i
"""Driver Code"""
if __name__ == "__main__":
# Array without duplicate elements
nums = [1, 3, 6, 8, 12, 15, 23, 26, 31, 35]
print(f"\nArray nums = {nums}")
# Binary search for insertion point
for target in [6, 9]:
index = binary_search_insertion_simple(nums, target)
print(f"Element {target}'s insertion point index is {index}")
# Array with duplicate elements
nums = [1, 3, 6, 6, 6, 6, 6, 10, 12, 15]
print(f"\nArray nums = {nums}")
# Binary search for insertion point
for target in [2, 6, 20]:
index = binary_search_insertion(nums, target)
print(f"Element {target}'s insertion point index is {index}")