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* Add the intial translation of code of all the languages * test * revert * Remove * Add Python and Java code for EN version
37 lines
1.1 KiB
Python
37 lines
1.1 KiB
Python
"""
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File: climbing_stairs_backtrack.py
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Created Time: 2023-06-30
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Author: krahets (krahets@163.com)
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"""
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def backtrack(choices: list[int], state: int, n: int, res: list[int]) -> int:
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"""Backtracking"""
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# When climbing to the nth step, add 1 to the number of solutions
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if state == n:
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res[0] += 1
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# Traverse all choices
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for choice in choices:
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# Pruning: do not allow climbing beyond the nth step
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if state + choice > n:
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continue
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# Attempt: make a choice, update the state
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backtrack(choices, state + choice, n, res)
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# Retract
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def climbing_stairs_backtrack(n: int) -> int:
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"""Climbing stairs: Backtracking"""
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choices = [1, 2] # Can choose to climb up 1 step or 2 steps
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state = 0 # Start climbing from the 0th step
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res = [0] # Use res[0] to record the number of solutions
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backtrack(choices, state, n, res)
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return res[0]
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"""Driver Code"""
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if __name__ == "__main__":
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n = 9
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res = climbing_stairs_backtrack(n)
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print(f"Climb {n} steps, there are {res} solutions in total")
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