字符排序

Question

我有個字符的字符串

abcdefghijklmnopqrstuvwxyz_

我想利用這個字符串和次數，他們出現在字符的大塊進行排序。例如：

cwrxwzbgickpjbp_svnudntddwdqbfgzyiqpuxddmpvyfquosmicfzkjekxzchngpqaksafulateukuwomdrwza_n_ptzktjzcuibnebe_tqessrzqewgkadrkvtyznaupodanwazopg_fijcoojojbsolr_ejesukzc_quochdnmti_lkvrsegyieqlqysuxdvetkqtkhxaiypfdiddztlicjurnllriopdtuuzpryrsepfydyeg_xkr_ruxp_lgqesysidfsygztwrba_ay_gaqqklbrvr_lbhawjraqujfxptmuvqfzklfodgaqrnhjravksjwemoosdlxtvw_qspxmlvqryusfixzlkb_p_c_tepzozzwnokvqspkizygoqpbhjnsxopchzgapctowbrletrunlgnvzpfwrqgedo_s_ygkxz_mpncnve_gfpbotupawevhfxvqhwlerupjfibosbvhiijrodigzyhy_iijes_xsqorshhdzkjqitpljsftpitjetwmzqiabyiewgtbjaddtsjkckcxxvlyrchloetluxkohn_uihkdjpcqgvejanslakmwendgkmvmayknvjjnr_kdapnumwvz__lsimxdtrflyleykxejl_jbkhexpcyreoapelqzzyriyrbxdgbgwrrxlj_pt_mpwubvbveakxfsbfgj___

我也想放棄任何字符後包括下劃線，一旦我有這些分類。

遞歸正確的想法，我需要看看這裏？

afiskjweocnsdkspwjrhfg

基本上字符將簡單地基於其在一個單一的線路頻率來排序：

EDIT的什麼可以被輸出

實施例。

Answer 1

<?php 

$text = 'ahugechunkofatext'; 
$charCounts = count_chars($text, 1); 
arsort($charCounts); 

$chars = array_map('chr', array_keys($charCounts)); 
$chars = array_filter($chars, function ($char) { 
    return !in_array($char, ['_']); // A list of chars that you don't want 
}); 

echo implode('', $chars) . PHP_EOL; 

Answer 2

你可以使用collections.Counter算在大字符串中的字符：

import collections 
walloftext = """cwrxwzbgickpjbp_svnudntddwdqbfgzyiqpuxddmpvyfquosmicfzkjekxzchngpqaksafulateukuwomdrwza_n_ptzktjzcuibnebe_tqessrzqewgkadrkvtyznaupodanwazopg_fijcoojojbsolr_ejesukzc_quochdnmti_lkvrsegyieqlqysuxdvetkqtkhxaiypfdiddztlicjurnllriopdtuuzpryrsepfydyeg_xkr_ruxp_lgqesysidfsygztwrba_ay_gaqqklbrvr_lbhawjraqujfxptmuvqfzklfodgaqrnhjravksjwemoosdlxtvw_qspxmlvqryusfixzlkb_p_c_tepzozzwnokvqspkizygoqpbhjnsxopchzgapctowbrletrunlgnvzpfwrqgedo_s_ygkxz_mpncnve_gfpbotupawevhfxvqhwlerupjfibosbvhiijrodigzyhy_iijes_xsqorshhdzkjqitpljsftpitjetwmzqiabyiewgtbjaddtsjkckcxxvlyrchloetluxkohn_uihkdjpcqgvejanslakmwendgkmvmayknvjjnr_kdapnumwvz__lsimxdtrflyleykxejl_jbkhexpcyreoapelqzzyriyrbxdgbgwrrxlj_pt_mpwubvbveakxfsbfgj___""" 
wallcount = collections.Counter(walloftext) 

然後使用這些計數到原來的字母排序：

alphabet = "abcdefghijklmnopqrstuvwxyz_" 
sortedalph = sorted(alphabet, key=lambda c: wallcount[c]) 

（此排序可通過提高頻率：結果如果你想反其道而行，請在wallcount之前投入-。）

最後，參加排序的字母回字符串後它砍掉下劃線和一切：

finalalph = "".join(sortedalph).split("_")[0]