394. Decode String

Topic

• Total accepted:10087
• Total submissions:25510
• Difficulty:medium
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Given an encoded string, return it s decoded string.

The encoding rule is: k[encoded_string] , where the encoded_string inside the square brackets is being repeated exactly k< /c3> times. Note that K was guaranteed to be a positive integer.

Assume that the input string was always valid; No extra white spaces, square brackets is well-formed, etc.

Furthermore, assume that the original data does not contain any digits and that digits is only for those repeat N Umbers, K. For example, there won ' t is input like 3a or 2[4] .

Examples:

s = "3[A]2[BC]", return "AAABCBC". S = "3[a2[c]", return "ACCACCACC". S = "2[abc]3[cd]ef", Return "Abcabccdcdcdef".

Solving

1 classSolution {2  Public:3     stringDecodestring (strings) {4stack<string>STRs;5stack<int>counts;6         stringresult ="";7         intCNT =0;8          for(inti =0; I < s.size (); i++) {9             if(S[i] <='9'&& S[i] >='0') {TenCNT = cnt*Ten+ S[i]-'0'; Onecout <<"Number ="<< CNT <<Endl; A}Else if(S[i] = ='[') { -cout <<"["<<Endl; - Counts.push (CNT); the Strs.push (result); - result.clear (); -CNT =0; -}Else if(S[i] = =']') { +                 intcur_cnt =counts.top (); -cout <<"]"<<"cur_cnt ="<< cur_cnt <<Endl; + Counts.pop (); A                  for(intj =0; J < cur_cnt; J + +) { atStrs.top () + =result; -                 } -result =strs.top (); - Strs.pop (); -}Else { -Result + =S[i]; incout <<"result + ="<< S[i] <<Endl; -             } to         } +         returnStrs.empty ()?result:strs.top (); -     } the};

Attention:

' [' Remember to clear result, initialize CNT to 0.

394. Decode String