mirror of https://github.com/TwoWater/Python
25 lines
361 B
Plaintext
25 lines
361 B
Plaintext
# Python3 program for Painting Fence Algorithm
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# optimised version
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# Returns count of ways to color k posts
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def countWays(n, k):
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dp = [0] * (n + 1)
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total = k
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mod = 1000000007
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dp[1] = k
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dp[2] = k * k
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for i in range(3,n+1):
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dp[i] = ((k - 1) * (dp[i - 1] + dp[i - 2])) % mod
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return dp[n]
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# Driver code
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n = 3
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k = 2
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print(countWays(n, k))
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