25 lines
550 B
Python
25 lines
550 B
Python
# sign function
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def sgn(x):
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if x>=0:
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return 1
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return -1
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# check whether a number is an integer (with tolerance)
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def isint_nonzero(x):
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if abs(x)<1e-11:
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return False
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return abs(round(x)-x)<1e-11
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# find the common substring in a list of strings
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def common_substr(strings):
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out=""
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if len(strings)==0:
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return out
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for i in range(len(strings[0])):
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for j in range(1,len(strings)):
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if strings[j][i]!=strings[0][i]:
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return out
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out+=strings[0][i]
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return out
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