把字符串转换成整数 (atoi)

/*
 * Approach using Java Streams:
 * 1. Discard leading whitespace characters.
 * 2. Use Streams to process the string and convert to integer.
 * 3. Handle sign and overflow conditions.
 */
import java.util.stream.IntStream;

public class SolutionStream {
    public int myAtoi(String s) {
        int[] result = {0}; // Using an array to capture result inside lambda
        int[] sign = {1};
        boolean[] started = {false};
        // Using Streams to iterate characters
        IntStream.range(0, s.length()).forEach(i -> {
            char c = s.charAt(i);
            if (!started[0] && c == ' ') return;
            if (!started[0] && (c == '+' || c == '-')) {
                sign[0] = c == '-' ? -1 : 1;
                started[0] = true;
                return;
            }
            if (Character.isDigit(c)) {
                started[0] = true;
                int digit = c - '0';
                if (result[0] > (Integer.MAX_VALUE - digit) / 10) {
                    result[0] = sign[0] == 1 ? Integer.MAX_VALUE : Integer.MIN_VALUE;
                    return;
                }
                result[0] = result[0] * 10 + digit;
            } else if (started[0]) {
                return;
            }
        });
        return result[0] * sign[0];
    }
}