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| class Solution {
public int myAtoi(String str) {
char[] chars = str.toCharArray();
int len = chars.length;
if (len == 0) {
return 0;
}
int index = 0;
while (index < len && chars[index] == ' ') {
index++;
}
if (index == len) {
return 0;
}
boolean negative = false;
if (chars[index] == '-') {
negative = true;
index++;
} else if (chars[index] == '+') {
index++;
} else if (!Character.isDigit(chars[index])) {
return 0;
}
int result = 0;
while (index < len && Character.isDigit(chars[index])) {
int digit = chars[index] - '0';
if (result > (Integer.MAX_VALUE - digit) / 10) {
return negative ? Integer.MIN_VALUE : Integer.MAX_VALUE;
}
result = result * 10 + digit;
index++;
}
return negative ? -result : result;
}
}
|
