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export default function restoreIpAddresses(s: string): string[] {    if (        s.length === 12 &&        (Number(s[0]) >= 3 ||            Number(s[3]) >= 3 ||            Number(s[6]) >= 3 ||            Number(s[9]) >= 3)    ) {        return [];    }    if (s.length < 4 || s.length > 12) return [];    if (s.length === 4) return [s.split("").join(".")];    const res: string[] = [];    dfs(s, [], (r) => res.push(r));    return res;}function dfs(s: string, address: number[], output: (r: string) => void) {    if (s.length === 0) {        if (address.length === 4) output(address.join("."));        else {            return;        }    }
    if (s.length > 3 * (4 - address.length) || s.length < 4 - address.length) {        return;    }
    if (s.startsWith("0")) {        dfs(s.slice(1), [...address, 0], output);        return;    }
    if (s.startsWith("1")) {        dfs(s.slice(1), [...address, 1], output);        if (s.length >= 2) {            dfs(s.slice(2), [...address, Number(s.slice(0, 2))], output);        }        if (s.length >= 3) {            dfs(s.slice(3), [...address, Number(s.slice(0, 3))], output);        }        return;    }
    for (const len of [1, 2, 3]) {        if (s.length >= len) {            const num = Number(s.slice(0, len));            if (0 <= num && num <= 255) {                dfs(s.slice(len), [...address, num], output);            }        }    }}