three_letters_combination();
function three_letters_combination()
{
$s = "abcdefghijklmnopqrstuvwxyz0123456789";
$s_size = strlen($s);
for ($i = 0; $i < $s_size; $i++)
{
for ($j = 0; $j < $s_size; $j++)
{
for ($k = 0; $k < $s_size; $k++)
{
echo $s[$i] . $s[$j] . $s[$k] . " ";
}
echo "<br />";
}
}
}
/*
run:
aaa aab aac aad aae aaf aag aah aai aaj aak aal aam aan aao aap aaq aar aas aat aau aav aaw aax aay aaz aa0 aa1 aa2 aa3 aa4 aa5 aa6 aa7 aa8 aa9
aba abb abc abd abe abf abg abh abi abj abk abl abm abn abo abp abq abr abs abt abu abv abw abx aby abz ab0 ab1 ab2 ab3 ab4 ab5 ab6 ab7 ab8 ab9
aca acb acc acd ace acf acg ach aci acj ack acl acm acn aco acp acq acr acs act acu acv acw acx acy acz ac0 ac1 ac2 ac3 ac4 ac5 ac6 ac7 ac8 ac9
ada adb adc add ade adf adg adh adi adj adk adl adm adn ado adp adq adr ads adt adu adv adw adx ady adz ad0 ad1 ad2 ad3 ad4 ad5 ad6 ad7 ad8 ad9
aea aeb aec aed aee aef aeg aeh aei aej aek ael aem aen aeo aep aeq aer aes aet aeu aev aew aex aey aez ae0 ae1 ae2 ae3 ae4 ae5 ae6 ae7 ae8 ae9
afa afb afc afd afe aff afg afh afi afj afk afl afm afn afo afp afq afr afs aft afu afv afw afx afy afz af0 af1 af2 af3 af4 af5 af6 af7 af8 af9
aga agb agc agd age agf agg agh agi agj agk agl agm agn ago agp agq agr ags agt agu agv agw agx agy agz ag0 ag1 ag2 ag3 ag4 ag5 ag6 ag7 ag8 ag9
aha ahb ahc ahd ahe ahf ahg ahh ahi ahj ahk ahl ahm ahn aho ahp ahq ahr ahs aht ahu ahv ahw ahx ahy ahz ah0 ah1 ah2 ah3 ah4 ah5 ah6 ah7 ah8 ah9
aia aib aic aid aie aif aig aih aii aij aik ail aim ain aio aip aiq air ais ait aiu aiv aiw aix aiy aiz ai0 ai1 ai2 ai3 ai4 ai5 ai6 ai7 ai8 ai9
aja ajb ajc ajd aje ajf ajg ajh aji ajj ajk ajl ajm ajn ajo ajp ajq ajr ajs ajt aju ajv ajw ajx ajy ajz aj0 aj1 aj2 aj3 aj4 aj5 aj6 aj7 aj8 aj9
aka akb akc akd ake akf akg akh aki akj akk akl akm akn ako akp akq akr aks akt aku akv akw akx aky akz ak0 ak1 ak2 ak3 ak4 ak5 ak6 ak7 ak8 ak9
ala alb alc ald ale alf alg alh ali alj alk all alm aln alo alp alq alr als alt alu alv alw alx aly alz al0 al1 al2 al3 al4 al5 al6 al7 al8 al9
ama amb amc amd ame amf amg amh ami amj amk aml amm amn amo amp amq amr ams amt amu amv amw amx amy amz am0 am1 am2 am3 am4 am5 am6 am7 am8 am9
ana anb anc and ane anf ang anh ani anj ank anl anm ann ano anp anq anr ans ant anu anv anw anx any anz an0 an1 an2 an3 an4 an5 an6 an7 an8 an9
aoa aob aoc aod aoe aof aog aoh aoi aoj aok aol aom aon aoo aop aoq aor aos aot aou aov aow aox aoy aoz ao0 ao1 ao2 ao3 ao4 ao5 ao6 ao7 ao8 ao9
apa apb apc apd ape apf apg aph api apj apk apl apm apn apo app apq apr aps apt apu apv apw apx apy apz ap0 ap1 ap2 ap3 ap4 ap5 ap6 ap7 ap8 ap9
aqa aqb aqc aqd aqe aqf aqg aqh aqi aqj aqk aql aqm aqn aqo aqp aqq aqr aqs aqt aqu aqv aqw aqx aqy aqz aq0 aq1 aq2 aq3 aq4 aq5 aq6 aq7 aq8 aq9
ara arb arc ard are arf arg arh ari arj ark arl arm arn aro arp arq arr ars art aru arv arw arx ary arz ar0 ar1 ar2 ar3 ar4 ar5 ar6 ar7 ar8 ar9
asa asb asc asd ase asf asg ash asi asj ask asl asm asn aso asp asq asr ass ast asu asv asw asx asy asz as0 as1 as2 as3 as4 as5 as6 as7 as8 as9
ata atb atc atd ate atf atg ath ati atj atk atl atm atn ato atp atq atr ats att atu atv atw atx aty atz at0 at1 at2 at3 at4 at5 at6 at7 at8 at9
aua aub auc aud aue auf aug auh aui auj auk aul aum aun auo aup auq aur aus aut auu auv auw aux auy auz au0 au1 au2 au3 au4 au5 au6 au7 au8 au9
ava avb avc avd ave avf avg avh avi avj avk avl avm avn avo avp avq avr avs avt avu avv avw avx avy avz av0 av1 av2 av3 av4 av5 av6 av7 av8 av9
awa awb awc awd awe awf awg awh awi awj awk awl awm awn awo awp awq awr aws awt awu awv aww awx awy awz aw0 aw1 aw2 aw3 aw4 aw5 aw6 aw7 aw8 aw9
axa axb axc axd axe axf axg axh axi axj axk axl axm axn axo axp axq axr axs axt axu axv axw axx axy axz ax0 ax1 ax2 ax3 ax4 ax5 ax6 ax7 ax8 ax9
aya ayb ayc ayd aye ayf ayg ayh ayi ayj ayk ayl aym ayn ayo ayp ayq ayr ays ayt ayu ayv ayw ayx ayy ayz ay0 ay1 ay2 ay3 ay4 ay5 ay6 ay7 ay8 ay9
aza azb azc azd aze azf azg azh azi azj azk azl azm azn azo azp azq azr azs azt azu azv azw azx azy azz az0 az1 az2 az3 az4 az5 az6 az7 az8 az9
a0a a0b a0c a0d a0e a0f a0g a0h a0i a0j a0k a0l a0m a0n a0o a0p a0q a0r a0s a0t a0u a0v a0w a0x a0y a0z a00 a01 a02 a03 a04 a05 a06 a07 a08 a09
a1a a1b a1c a1d a1e a1f a1g a1h a1i a1j a1k a1l a1m a1n a1o a1p a1q a1r a1s a1t a1u a1v a1w a1x a1y a1z a10 a11 a12 a13 a14 a15 a16 a17 a18 a19
...
*/
