bg090721 发表于 2013-1-26 12:28:55

bit count in c (2) -

 pre
  Precompute_16bit.c
  Precompute_8bit.c

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Precompute_16bit.c
#include <stdio.h>#include <stdlib.h>#include <time.h>#include "../lib/ut.h"//int main(void) {int Precompute_16bit(void) {int max = 0x1u << 16;FILE * pFile;pFile = fopen ("src/lib/pre16.h","w");int i;fprintf(pFile, "#ifndef PRE16_H_\n");fprintf(pFile, "#define PRE16_H_\n\n");fprintf(pFile, "static int bits_in_16bits [%d]={\n", max);for (i = 0; i < max; i++) {    if (i > 0) {      if(i%32==0){      fprintf(pFile, "\n");      }      fprintf(pFile, ", ");    }    int rlt = a2_bitcount(i);    fprintf(pFile, "%d", rlt);}fprintf(pFile, "\n};\n\n");fprintf(pFile, "#endif /* PRE16_H_ */\n");fclose (pFile);return EXIT_SUCCESS;} 
Precompute_8bit.c
#include <stdio.h>#include <stdlib.h>#include <time.h>#include "../lib/ut.h"//int main(void) {int Precompute_8bit(void) {int max = 256;FILE * pFile;pFile = fopen ("src/lib/pre8.h","w");int i;fprintf(pFile, "#ifndef PRE8_H_\n");fprintf(pFile, "#define PRE8_H_\n\n");fprintf(pFile, "static int bits_in_char [%d]={\n", max);for (i = 0; i < max; i++) {    if (i > 0) {      if(i%32==0){      fprintf(pFile, "\n");      }      fprintf(pFile, ", ");    }    int rlt = a2_bitcount(i);    fprintf(pFile, "%d", rlt);}fprintf(pFile, "\n};\n\n");fprintf(pFile, "#endif /* PRE8_H_ */\n");fclose (pFile);return EXIT_SUCCESS;}
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