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export default function myAtoi(s: string): number {    s = s.trimStart();    if (s.length === 0) {        return 0;    }    let positive = true;    if (s.startsWith("+")) {        positive = true;        s = s.slice(1);    } else if (s.startsWith("-")) {        positive = false;        s = s.slice(1);    }    const numberchars = [];    while (intchars.includes(s[0])) {        numberchars.push(s[0]);
        s = s.slice(1);    }    if (numberchars.length === 0) return 0;    // let num=Number(numberchars.join(''))    let num = 0;    for (const n of numberchars) {        num *= 10;        // num+=Number(n)        num += intchartonum.get(n) || 0;    }    if (!positive) {        num = -1 * num;    }    return Math.max(-(2 ** 31), Math.min(num, 2 ** 31 - 1));}const intchars = Array.from({ length: 10 }).map((_v, i) => String(i));const intchartonum = new Map([...intchars.entries()].map(([a, b]) => [b, a]));