package code.leetcode.easy.string;

public class Atoi {

public static void main(String[] args) {

// myAtoi("-2147483649");

// myAtoi("2147483648");

// myAtoi("-2147483648");

// System.out.println(myAtoi(" -11919730356x") == -2147483648);

System.out.println(myAtoi(" 10522545459") == 2147483647);

}

public static int myAtoi(String str) {

if (str == null || str.length() < 1)

return 0;

char[] c = str.toCharArray();

boolean minus = false;

int firstInd = -1;

for (int i = 0; i < c.length && c[i] == ' '; i++)

firstInd = i;

char sign = c[++firstInd];

int signNum = 1;

if (sign == '-') {

minus = true;

signNum = -1;

firstInd++;

} else if (sign == '+')

firstInd++;

else if (sign < '0' || sign > '9')

return 0;

StringBuilder sb = new StringBuilder();

for (int i = firstInd; i < c.length; i++) {

if (c[i] < '0' || c[i] > '9')

break;

sb.append(c[i]);

}

if (sb.length() == 0)

return 0;

else if (sb.length() > 10)

return minus ? Integer.MIN_VALUE : Integer.MAX_VALUE;

int result = 0;

for (char d : sb.toString().toCharArray())

result = result * 10 + signNum * (d - '0');

if (minus && result > 0)

return Integer.MIN_VALUE;

else if (!minus && result < 0)

return Integer.MAX_VALUE;

return result;

}

}