LeetCode8 String to Integer (atoi)

Test instructions

Implement atoi to convert a string to an integer. (easy)

Analysis:

is to pay attention to a variety of special cases, boundary conditions of the judgment, see code comments.

1 classSolution {2  Public:3     intMyatoi (stringstr) {4         intStart =0;5         Long Longresult =0;6         intFlag =0;7         //handling of extra spaces at the beginning8          while(Str[start] = =' ') {                                     9start++;Ten         } One         if(Str[start] = ='+') { Astart++; -         } -         //"+-2" case, else if ... the         Else if(Str[start] = ='-') {                                    -start++; -Flag =1; -         } +         //illegal characters appear at the beginning -         if(Str[start] <'0'|| Str[start] >'9') {                      +             return 0; A         } at         //after the +-number processing, the extra 0 is started. -          while(Str[start] = ='0') {                                      -start++; -         } -          for(inti = start; I < str.size (); ++i) { -             //you can have extra numbers later . in             if(Str[i] <'0'|| Str[i] >'9') {                          -                 return(Flag = =0) ? Result:-result; to             } +             inttemp = Str[i]-'0'; -             //In this way, do not use POW (x, y) theresult = result *Ten+temp; *             //Handling of overflow $             if(Result >0x7FFFFFFF ) {                                 Panax Notoginseng                 return(Flag = =0) ?0x7FFFFFFF:0x80000000; -             } the         } +         if(Flag = =0) { A             returnresult;  the         } +         Else { -             return-result; $         } $  -     } -};

LeetCode8 String to Integer (atoi)