stringToIntegerAtoi.java
· 1.3 KiB · Java
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// https://leetcode.com/problems/string-to-integer-atoi/
class Solution {
public int myAtoi(String s) {
if (s == null || s.length() == 0) {
return 0;
}
var chars = s.toCharArray();
var reading_pointer = 0;
var charsLength = chars.length;
while (reading_pointer < charsLength && chars[reading_pointer] == ' ') {
reading_pointer += 1;
}
if (reading_pointer == charsLength) {
return 0;
}
var sign = 1;
if (chars[reading_pointer] == '-') {
sign = -1;
reading_pointer += 1;
} else if (chars[reading_pointer] == '+') {
sign = 1;
reading_pointer += 1;
}
long answerLong = 0;
while (reading_pointer < charsLength && Character.isDigit(chars[reading_pointer])) {
var digit = chars[reading_pointer] - '0';
answerLong = answerLong * 10 + digit;
if (sign * answerLong >= Integer.MAX_VALUE) {
return Integer.MAX_VALUE;
} else if (sign * answerLong <= Integer.MIN_VALUE) {
return Integer.MIN_VALUE;
}
reading_pointer += 1;
}
return sign * (int) answerLong;
}
}
| 1 | // https://leetcode.com/problems/string-to-integer-atoi/ |
| 2 | |
| 3 | class Solution { |
| 4 | |
| 5 | public int myAtoi(String s) { |
| 6 | if (s == null || s.length() == 0) { |
| 7 | return 0; |
| 8 | } |
| 9 | |
| 10 | var chars = s.toCharArray(); |
| 11 | |
| 12 | var reading_pointer = 0; |
| 13 | var charsLength = chars.length; |
| 14 | |
| 15 | while (reading_pointer < charsLength && chars[reading_pointer] == ' ') { |
| 16 | reading_pointer += 1; |
| 17 | } |
| 18 | if (reading_pointer == charsLength) { |
| 19 | return 0; |
| 20 | } |
| 21 | |
| 22 | var sign = 1; |
| 23 | if (chars[reading_pointer] == '-') { |
| 24 | sign = -1; |
| 25 | reading_pointer += 1; |
| 26 | } else if (chars[reading_pointer] == '+') { |
| 27 | sign = 1; |
| 28 | reading_pointer += 1; |
| 29 | } |
| 30 | |
| 31 | long answerLong = 0; |
| 32 | while (reading_pointer < charsLength && Character.isDigit(chars[reading_pointer])) { |
| 33 | var digit = chars[reading_pointer] - '0'; |
| 34 | answerLong = answerLong * 10 + digit; |
| 35 | |
| 36 | if (sign * answerLong >= Integer.MAX_VALUE) { |
| 37 | return Integer.MAX_VALUE; |
| 38 | } else if (sign * answerLong <= Integer.MIN_VALUE) { |
| 39 | return Integer.MIN_VALUE; |
| 40 | } |
| 41 | |
| 42 | reading_pointer += 1; |
| 43 | } |
| 44 | |
| 45 | return sign * (int) answerLong; |
| 46 | } |
| 47 | } |
| 48 |