12 lines
294 B
Ruby
12 lines
294 B
Ruby
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#Given a number "n",count the number of set bits in it.
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#Algorithm: Brian Kernighan's method(set count=0 ,while n>0 set n:=n&(n-1) and increment count, return count)
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#Time-complexity:O(logn)
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def count_set_bits(num)
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count=0
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while num>0
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num&=(num-1)
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count+=1
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end
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return count
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end
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