[Leetcode] Classic algorithmic question-String to Integer (atoi)

Title Description: Convert String to Integer value original description: Implement atoi to convert a string to an integer. Hint:

Carefully consider all possible input cases. If you want a challenge, please don't see below and ask yourself what is the possible input cases.

Notes:

It is intended for the problem to be specified vaguely (ie, no given input specs). You is responsible to gather all the input requirements up front.

Thinking Analysis:

• First judgment is empty, return 0
• Consider the space above, use trim () to remove, and then determine whether the length is 0, yes, return 0
• Determine if the first character is A + and-, set the variable sign record.
• Loop gets the number of the string, considering that there is a non-digit in the string, to exit, to retain the preceding number
• Overflow returns the maximum and minimum values for an integer, considering overflow conditions

Code implementation:

 Public  class solution {     Public intMyatoi (StringStr) {//To determine the null value first        if(Str==NULL){return 0; }//The case of removing spaces        Str=Str. Trim ();if(Str. Length () = =0){return 0; }intSign =1;int Index=0;if(Str. CharAt (Index) ==' + '){Index++; }Else if(Str. CharAt (Index) =='-'){Index++; Sign =-1; }//Get digital part, encounter overflow and non-digital exit        LongNumber =0; for(;Index<Str. Length ();Index++){if(Str. CharAt (Index) <' 0 '||Str. CharAt (Index) >' 9 '){ Break; } number = number *Ten+ (Str. CharAt (Index) -' 0 ');if(Number >= Integer.max_value) { Break; }        }if(number * Sign >= integer.max_value) {returnInteger.max_value; }if(number * Sign <= integer.min_value) {returnInteger.min_value; }return(int) Number*sign; }}

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[Leetcode] Classic algorithmic question-String to Integer (atoi)