Leetcode-fraction to recurring Decimal

Given integers representing the numerator and denominator of a fraction, return the fraction in string format.

If the fractional part was repeating, enclose the repeating part in parentheses.

For example,

• Given numerator = 1, denominator = 2, return "0.5".
• Given numerator = 2, denominator = 1, return "2".
• Given numerator = 2, denominator = 3, return "0. (6) ".

Analysis:

We need to use long type.

Solution:

Store every digit in float part, and assemble the string at last.

1  Public classSolution {2      PublicString Fractiontodecimal (intNumerator,intdenominator) {3         if(denominator==0)return"";4         if(numerator==0)return"0";5         BooleanNeg =false;6         if(numerator>0){7Numerator =-numerator;8NEG =!neg;9         }Ten  One         if(denominator>0){ ADenominator =-denominator; -NEG =!neg; -         } the   -  -         LongIntpart = (Long) numerator/(Long) denominator; -         Longleft = numerator%denominator; +  -List<integer> digitlist =NewArraylist<integer>(); +List<long> leftlist =NewArraylist<long>(); A         intIterstart =-1; at          while(left!=0){ -             intDigit = (int) (left*10/denominator); - digitlist.add (digit); - Leftlist.add (left); -             LongNewleft = (left*10)%denominator; -             if(Leftlist.contains (newleft)) { inIterstart =Leftlist.indexof (newleft); -                  Break; to             } +left =Newleft; -         } the  *         //Assemble the string. $StringBuilder Builder =NewStringBuilder ();Panax Notoginseng         if(neg) builder.append ('-')); - builder.append (intpart); the  +         if(Digitlist.size () ==0)returnbuilder.tostring (); A         Else { theBuilder.append ('. ')); +             if(Iterstart==-1) -                  for(intI=0;i<digitlist.size (); i++) $ Builder.append (Digitlist.get (i)); $             Else { -                 //append non-iter part. -                  for(inti=0;i<iterstart;i++) the Builder.append (Digitlist.get (i)); -Builder.append (' (');Wuyi                 //append iter part. the                  for(intI=iterstart;i<digitlist.size (); i++) - Builder.append (Digitlist.get (i)); WuBuilder.append (') '); -             } About             returnbuilder.tostring (); $        }         -          -     } -}

Solution 2:

Store the postion of the corresponding left of every digit, assemble the result string in place.

1  Public classSolution {2      PublicString Fractiontodecimal (LongNumerator,Longdenominator) {3         if(denominator==0)return"";4         if(numerator==0)return"0";5String res = "";6         if(numerator<0 ^ denominator<0)7res = "-"; 8  9Numerator =Math.Abs (numerator);TenDenominator =Math.Abs (denominator); One  A         LongIntpart = numerator/denominator; -         Longleft = numerator%denominator; -res =Res.concat (long.tostring (Intpart)); theMap<long,integer> Posmap =NewHashmap<long,integer>(); -         if(left!=0) res = Res.concat (".")); -          while(left!=0){ -             Longdigit = left*10/denominator; + Posmap.put (Left,res.length ()); -res =Res.concat (long.tostring (digit)); +left = left*10%denominator; A             if(Posmap.containskey (left)) { at                 intpos =Posmap.get (left); -res = res.substring (0,pos) + "(" +res.substring (Pos,res.length ()) + ")"; -left = 0; -             } -         }             -  in         returnRes;  -          to     } +}

Leetcode-fraction to recurring Decimal