StringToInteger.cpp

/*Implement the myAtoi(string s) function, which converts a string to a 32-bit signed integer.

The algorithm for myAtoi(string s) is as follows:

Whitespace: Ignore any leading whitespace (" ").
Signedness: Determine the sign by checking if the next character is '-' or '+', assuming positivity is neither present.
Conversion: Read the integer by skipping leading zeros until a non-digit character is encountered or the end of the string is reached. If no digits were read, then the result is 0.
Rounding: If the integer is out of the 32-bit signed integer range [-231, 231 - 1], then round the integer to remain in the range. Specifically, integers less than -231 should be rounded to -231, and integers greater than 231 - 1 should be rounded to 231 - 1.
Return the integer as the final result.*/

class Solution {
public:
    int myAtoi(string s) {
          int i = 0;
    int n = s.length();
    int sign = 1;
    long result = 0;
    
    
    while (i < n && s[i] == ' ') {
        i++;
    }

    if (i < n && (s[i] == '+' || s[i] == '-')) {
        sign = (s[i] == '-') ? -1 : 1;
        i++;
    }
    while (i < n && isdigit(s[i])) {
        int digit = s[i] - '0';
        result = result * 10 + digit;
        
     
        if (result * sign > INT_MAX) {
            return INT_MAX;
        } else if (result * sign < INT_MIN) {
            return INT_MIN;
        }
        
        i++;
    }
    
    return result * sign;
    }
};