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20 lines
383 B
20 lines
383 B
10 years ago
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#pragma once
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template <typename Int>
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bool is_pow_of_two(Int n){
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return n && !(n & (n - 1));
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}
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template <typename Int>
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bool is_even(Int n){
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return (n & 1) == 0;
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}
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// calculates integer 2-log such that:
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// 2^(two_log(x)) >= x > 2^(two_log(x) - 1)
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inline unsigned int two_log(unsigned int x){
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if(x <= 1) return 0;
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return 8*sizeof(unsigned int) - unsigned(__builtin_clz(x-1));
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}
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