Leetcode8--->string to integer (convert strings to integers)

topic: Implementing String-to-integer conversions

Problem Solving Ideas:

Here are some details that should be noted in this question:

1. String "123" = 123;

2. String "+123" = 123;

3. String "123" =-123;

4. String "-" = 0; "+" = 0;

5. String "123-" = 123;

6. String "21474836478" = 2147483647 (Integer.max_value)

7. The remaining cases are illegal inputs and return 0;

The code is as follows:

1  Public classSolution {2      Public intmyatoi (String str) {3         if(str = =NULL|| Str.length () < 1)4             return0;5         BooleanNegative =false;6         inti = 0;7         Doubleres = 0.0;8String s =Str.trim ();9         intLength =s.length ();Ten         if(S.charat (i) < ' 0 '){ One             if(S.charat (i) = = '-'){ ANegative =true; -             } -             Else if(S.charat (i)! = ' + '){ the                 return0; -             } -             if(Length = = 1) -                 return0; +i++; -         } +          while(I <length) { A             intn = (S.charat (i)-' 0 ') ; at             if(n >= 0 && N <= 9){ -Res *= 10; -Res + =N; -i + +; -             } -             Else in                  Break; -  to         } +         if(negative) { -Res *=-1; the         } *res = res >= integer.max_value?Integer.MAX_VALUE:res; $res = res <= integer.min_value?Integer.MIN_VALUE:res;Panax Notoginseng         return(int) Res; -     } the}

Leetcode8--->string to integer (convert strings to integers)