hash.c

快速傅立叶变换程序代码,学信号的同学,可要注意了

/*

DJCM 99 06 25 

    Hash functions stolen from Niemann or made by DJCM

 */
#include        <stdio.h>
#include        <math.h>
#include <stdlib.h>
#include <string.h>
#include <memory.h>


#include "./hash.h"  
#define HashTableSize N
/* this hash function is 'good' */
int hash(char *str , int N) {
  int h;
  unsigned char h1, h2;

  if (*str == 0) return 0;
  h1 = *str; h2 = *str + 1;
  str++;
  /*  printf("%d:%d\n", h1, h2 ) ; */
  while (*str) {
    h1 = Rand8[h1 ^ *str];
    h2 = Rand8[h2 ^ *str];
    str++;
    /*    printf("%d:%d\n", h1, h2 ) ; */
  }
      
  /* h is in range 0..65535 */
  h = ((int)h1 << 8)|(int)h2;
  /* use division method to scale */
  return h % HashTableSize ;
}
/* this hash function is 'bad' in that it loves anagrams */
int chash(char *str , int N) {
  int h;
  unsigned char h1, h2;

  if (*str == 0) return 0;
  h1 = *str; h2 = Rand8[*str] ;
  str++;
  while (*str) {
    h1 ^= *str;
    h2 ^= Rand8[*str];
    str++;
  }
      
  /* h is in range 0..65535 */
  h = ((int)h1 << 8)|(int)h2;
  /* use division method to scale */
  return h % HashTableSize ;
}

void loadRand8 (void) {
Rand8[1]=132;
Rand8[2]=45;
Rand8[3]=80;
Rand8[4]=139;
Rand8[5]=243;
Rand8[6]=44;
Rand8[7]=181;
Rand8[8]=59;
Rand8[9]=127;
Rand8[10]=31;
Rand8[11]=21;
Rand8[12]=102;
Rand8[13]=73;
Rand8[14]=97;
Rand8[15]=252;
Rand8[16]=142;
Rand8[17]=198;
Rand8[18]=168;
Rand8[19]=199;
Rand8[20]=202;
Rand8[21]=213;
Rand8[22]=38;
Rand8[23]=161;
Rand8[24]=82;
Rand8[25]=90;
Rand8[26]=235;
Rand8[27]=134;
Rand8[28]=104;
Rand8[29]=157;
Rand8[30]=204;
Rand8[31]=239;
Rand8[32]=223;
Rand8[33]=222;
Rand8[34]=172;
Rand8[35]=192;
Rand8[36]=147;
Rand8[37]=96;
Rand8[38]=87;
Rand8[39]=49;
Rand8[40]=212;
Rand8[41]=106;
Rand8[42]=117;
Rand8[43]=251;
Rand8[44]=28;
Rand8[45]=53;
Rand8[46]=246;
Rand8[47]=186;
Rand8[48]=103;
Rand8[49]=197;
Rand8[50]=190;
Rand8[51]=245;
Rand8[52]=6;
Rand8[53]=77;
Rand8[54]=189;
Rand8[55]=60;
Rand8[56]=149;
Rand8[57]=10;
Rand8[58]=244;
Rand8[59]=78;
Rand8[60]=14;
Rand8[61]=113;
Rand8[62]=232;
Rand8[63]=145;
Rand8[64]=27;
Rand8[65]=144;
Rand8[66]=63;
Rand8[67]=125;
Rand8[68]=57;
Rand8[69]=121;
Rand8[70]=101;
Rand8[71]=224;
Rand8[72]=109;
Rand8[73]=88;
Rand8[74]=94;
Rand8[75]=9;
Rand8[76]=39;
Rand8[77]=137;
Rand8[78]=178;
Rand8[79]=23;
Rand8[80]=105;
Rand8[81]=201;
Rand8[82]=61;
Rand8[83]=85;
Rand8[84]=55;
Rand8[85]=74;
Rand8[86]=76;
Rand8[87]=228;
Rand8[88]=8;
Rand8[89]=170;
Rand8[90]=110;
Rand8[91]=176;
Rand8[92]=188;
Rand8[93]=240;
Rand8[94]=56;
Rand8[95]=216;
Rand8[96]=249;
Rand8[97]=200;
Rand8[98]=115;
Rand8[99]=171;
Rand8[100]=209;
Rand8[101]=35;
Rand8[102]=68;
Rand8[103]=30;
Rand8[104]=221;
Rand8[105]=191;
Rand8[106]=48;
Rand8[107]=32;
Rand8[108]=72;
Rand8[109]=207;
Rand8[110]=52;
Rand8[111]=150;
Rand8[112]=180;
Rand8[113]=46;
Rand8[114]=255;
Rand8[115]=65;
Rand8[116]=118;
Rand8[117]=193;
Rand8[118]=220;
Rand8[119]=230;
Rand8[120]=250;
Rand8[121]=100;
Rand8[122]=116;
Rand8[123]=25;
Rand8[124]=123;
Rand8[125]=58;
Rand8[126]=254;
Rand8[127]=163;
Rand8[128]=154;
Rand8[129]=54;
Rand8[130]=122;
Rand8[131]=203;
Rand8[132]=15;
Rand8[133]=129;
Rand8[134]=33;
Rand8[135]=64;
Rand8[136]=238;
Rand8[137]=158;
Rand8[138]=253;
Rand8[139]=128;
Rand8[140]=205;
Rand8[141]=183;
Rand8[142]=93;
Rand8[143]=126;
Rand8[144]=138;
Rand8[145]=17;
Rand8[146]=153;
Rand8[147]=86;
Rand8[148]=26;
Rand8[149]=196;
Rand8[150]=177;
Rand8[151]=114;
Rand8[152]=174;
Rand8[153]=16;
Rand8[154]=242;
Rand8[155]=143;
Rand8[156]=184;
Rand8[157]=148;
Rand8[158]=162;
Rand8[159]=206;
Rand8[160]=40;
Rand8[161]=71;
Rand8[162]=67;
Rand8[163]=169;
Rand8[164]=70;
Rand8[165]=146;
Rand8[166]=107;
Rand8[167]=75;
Rand8[168]=112;
Rand8[169]=151;
Rand8[170]=130;
Rand8[171]=160;
Rand8[172]=98;
Rand8[173]=19;
Rand8[174]=50;
Rand8[175]=3;
Rand8[176]=248;
Rand8[177]=20;
Rand8[178]=92;
Rand8[179]=173;
Rand8[180]=84;
Rand8[181]=155;
Rand8[182]=89;
Rand8[183]=156;
Rand8[184]=131;
Rand8[185]=29;
Rand8[186]=167;
Rand8[187]=36;
Rand8[188]=159;
Rand8[189]=66;
Rand8[190]=229;
Rand8[191]=225;
Rand8[192]=219;
Rand8[193]=233;
Rand8[194]=164;
Rand8[195]=136;
Rand8[196]=24;
Rand8[197]=182;
Rand8[198]=187;
Rand8[199]=47;
Rand8[200]=12;
Rand8[201]=217;
Rand8[202]=37;
Rand8[203]=108;
Rand8[204]=83;
Rand8[205]=226;
Rand8[206]=18;
Rand8[207]=62;
Rand8[208]=34;
Rand8[209]=135;
Rand8[210]=99;
Rand8[211]=141;
Rand8[212]=140;
Rand8[213]=91;
Rand8[214]=165;
Rand8[215]=11;
Rand8[216]=166;
Rand8[217]=194;
Rand8[218]=214;
Rand8[219]=175;
Rand8[220]=79;
Rand8[221]=227;
Rand8[222]=179;
Rand8[223]=43;
Rand8[224]=210;
Rand8[225]=133;
Rand8[226]=231;
Rand8[227]=237;
Rand8[228]=236;
Rand8[229]=2;
Rand8[230]=215;
Rand8[231]=241;
Rand8[232]=152;
Rand8[233]=7;
Rand8[234]=42;
Rand8[235]=13;
Rand8[236]=51;
Rand8[237]=218;
Rand8[238]=120;
Rand8[239]=1;
Rand8[240]=41;
Rand8[241]=4;
Rand8[242]=111;
Rand8[243]=195;
Rand8[244]=124;
Rand8[245]=185;
Rand8[246]=22;
Rand8[247]=247;
Rand8[248]=5;
Rand8[249]=69;
Rand8[250]=119;
Rand8[251]=211;
Rand8[252]=81;
Rand8[253]=234;
Rand8[254]=0;
Rand8[255]=95;
Rand8[0]=208;
}