#include?“arithmetic.h“

void?Arithmetic::getProbabilities（char?*str）?{
????char?ch;
????double?lowLevel?=?0.0;
????double?highLevel?=?0.0;
????double?probability;
????int?freq[128]?=?{0};
????for?（int?i?=?0;?str[i];?i++）
????????freq[str[i]]++;
????cout?<????for?（int?i?=?0;?i?????????if?（freq[i]）?{
????????????ch?=?（char）?i;
????????????probability?=?（double）?freq[i]?/?（double）?strlen（str）;
????????????cout?<????????????lowLevel?=?highLevel;
????????????highLevel?=?lowLevel?+?probability;
????????????Range?range;
????????????range.setLow（lowLevel）;
????????????range.setHigh（highLevel）;
????????????range.setDelta（probability）;
????????????map.insert（std::pair（ch?range））;
????????}
????}
}

double?Arithmetic::encode（string?str）?{
????double?lowRange?=?0.0?highRange?=?1.0;
????for?（char?&i?:?str）?{
????????//?使用map來通過字符完成概率的查找
????????//?map[*i]表示的就是對應的字符的出現概率
????????double?delta?=?highRange?-?lowRange;
????????highRange?=?lowRange?+?delta?*?map[i].getHigh（）;
????????lowRange?=?lowRange?+?delta?*?map[i].getLow（）;
????????++length;
????}
????return?lowRange;
}

void?Arithmetic::runArithmetic（）?{
????long?beginT?=?clock（）;
????cout?<????char?str[1024];
????cin>>str;
????getProbabilities（str）;
????long?endT?=?clock（）;
????long?costT?=?endT?-?beginT;
????cout?<????cout?<????dec2bin（encode（str））;
????cout<????cout?<????cout?<????cin.clear（）;
????cin.sync（）;
}


void?Arithmetic::dec2bin（double?n）?{
????stack?s;
????int?m?=?（int）?n;
????double?t?=?n?-?m;//0.4
????binLength?=?0;
????while?（m）??????????????????????????//?處理整數
????{
????????s.push（m?%?2）;
????????m?/=?2;
????}
????while?（!s.empty（））?{
????????printf（“%d“?s.top（））;

????????s.pop（）;
????}
????printf（“0.“）;
????while?（t?-?int（t）?!=?0）????????????????//處理小數點后的位數，乘2取整法?，當乘2變為整數后結束
????{
????????int?temp?=?int（t?*?2）;
????????printf（“%d“?temp）;
????????binLength++;
????????t?=?2?*?t?-?int（2?*?t）;
????}
}

?屬性????????????大小?????日期????時間???名稱
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?????文件????????2433??2018-12-22?00:16??arithmetic.cpp
?????文件????????1216??2018-12-21?23:29??arithmetic.h