41 lines
908 B
C
41 lines
908 B
C
/*
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* zzero - check how many bits zzuf changes in a stream of zeroes
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*
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* Copyright © 2002—2015 Sam Hocevar <sam@hocevar.net>
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*
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* This program is free software. It comes without any warranty, to
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* the extent permitted by applicable law. You can redistribute it
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* and/or modify it under the terms of the Do What the Fuck You Want
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* to Public License, Version 2, as published by the WTFPL Task Force.
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* See http://www.wtfpl.net/ for more details.
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*/
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#include "config.h"
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#include <stdio.h>
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#include <stdlib.h>
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#include <stdint.h>
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static inline int countones(uint8_t x)
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{
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static int const lut[16] =
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{
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0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4
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};
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return lut[x & 0xf] + lut[x >> 4];
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}
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int main(void)
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{
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int total = 0, ch;
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while ((ch = getc(stdin)) != EOF)
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total += countones((uint8_t)ch);
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printf("%i\n", total);
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return EXIT_SUCCESS;
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}
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