Révision 30

Pi/C/Simple/Pi.c (revision 30)
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#include <math.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <limits.h>
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// Marsaglia RNG very simple implementation


  		





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#define znew  ((z=36969*(z&65535)+(z>>16))<<16)


  		





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#define ITERATIONS 1000000000


  		





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#ifdef LONG


  		





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#define LENGTH unsigned long


  		





  
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#define LENGTH long long


  		





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#else


  		





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#define LENGTH unsigned int


  		





  
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#define LENGTH int


  		





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#endif


  		





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LENGTH MainLoopGlobal(LENGTH iterations,unsigned int seed_w,unsigned int seed_z)


  		





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   unsigned int z=seed_z;


  		





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   unsigned int w=seed_w;


  		





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   unsigned  long total=0;


  		





  
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   LENGTH total=0;


  		





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   for (LENGTH i=0;i<iterations;i++) {


  		





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  LENGTH iterations=ITERATIONS;


  		





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  if (argc > 1) {


  		





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    iterations=(LENGTH)atol(argv[1]);


  		





  
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    iterations=(LENGTH)atoll(argv[1]);


  		





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  }


  		





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  else {


  		





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    printf("\n\tPi : Estimate Pi with Monte Carlo exploration\n\n\t\t#1 : number of iterations (default 1 billion)\n\n");


  		





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  }


  		





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  printf ("\n\tInformation about architecture:\n\n");


  		





  
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  printf ("\tSizeof int = %lld bytes.\n", (long long)sizeof(int));


  		





  
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  printf ("\tSizeof long = %lld bytes.\n", (long long)sizeof(long));


  		





  
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  printf ("\tSizeof long long = %lld bytes.\n\n", (long long)sizeof(long long));


  		





  
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  printf ("\tMax int = %u\n", INT_MAX);


  		





  
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  printf ("\tMax long = %ld\n", LONG_MAX);


  		





  
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  printf ("\tMax long long = %lld\n\n", LLONG_MAX);


  		





  
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  float pi=(float)MainLoopGlobal(iterations,seed_w,seed_z)/(float)iterations*4;


  		





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  printf("\tPi=%.40f\n\twith error %.40f\n\twith %lu iterations\n\n",pi,


  		





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         fabs(pi-4*atan(1))/pi,(unsigned long)iterations);


  		





  
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  printf("\tPi=%.40f\n\twith error %.40f\n\twith %lld iterations\n\n",pi,


  		





  
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         fabs(pi-4*atan(1))/pi,(long long)iterations);


  		





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}


  		












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