ranint.c

用C语言编写的交织器

// ------------------------------------------------------------------------

// File: ranint.c

// Description: Generate a RANDOM interleaver. Output is the interleaver

// array in a file with name specified at command line

// 



#include <stdio.h>

#include <math.h>

#include <float.h>

#include <limits.h>



#define MAX_RANDOM LONG_MAX 

#define NMAX 16384



main(int argc, char *argv[])

{



int interleaver[NMAX];

int check[NMAX];                       // Already permuted positions

int i;

int position;

long seed;

int N;                                 // Interleaver length

char name1[40];

FILE *fp1;



  // Command line processing

  if (argc != 4)

    {

      printf("Usage %s Int_length INT_file seed \n", argv[0]);

      exit(0);

    }



  sscanf(argv[1],"%d", &N);

  sscanf(argv[2],"%s", name1);

  sscanf(argv[3],"%ld", &seed);



  fp1 = fopen(name1,"w");



  srandom(seed);



  for (i=0; i<N; i++)

    check[i] = 0;



  for (i=0; (i<N); i++)

    {

      do

        position = (int) ( ( (double)(random())/MAX_RANDOM ) * N );

      while ( check[position] );

  

      printf("%d\n", i);



      // Write interleaver and deinterleaver

      check[position] = 1;			

      interleaver[i] = position;

    }    



  for (i=0; i<N; i++)

    {

      fprintf(fp1, "%d\n", interleaver[i]);

      printf("%5d -> %5d\n",i,interleaver[i]);

    }



  fclose(fp1);



}