Encode and Decode Strings

class Codec {
public:
    string encode(vector<string>& strs) {
        string out;
        for (auto& s : strs) {
            out += to_string(s.size());
            out += '#';
            out += s;
        }
        return out;
    }
    vector<string> decode(string s) {
        vector<string> out;
        int i = 0, n = s.size();
        while (i < n) {
            int j = s.find('#', i);
            int len = stoi(s.substr(i, j - i));
            out.push_back(s.substr(j + 1, len));
            i = j + 1 + len;
        }
        return out;
    }
};

import "strconv"

type Codec struct{}

func Constructor() Codec {
    return Codec{}
}

func (c *Codec) Encode(strs []string) string {
    out := ""
    for _, s := range strs {
        out += strconv.Itoa(len(s)) + "#" + s
    }
    return out
}

func (c *Codec) Decode(s string) []string {
    out := []string{}
    i, n := 0, len(s)
    for i < n {
        j := i
        for s[j] != '#' {
            j++
        }
        length, _ := strconv.Atoi(s[i:j])
        out = append(out, s[j+1:j+1+length])
        i = j + 1 + length
    }
    return out
}

from typing import List

class Codec:
    def encode(self, strs: List[str]) -> str:
        out = []
        for s in strs:
            out.append(f"{len(s)}#{s}")
        return "".join(out)

    def decode(self, s: str) -> List[str]:
        out = []
        i, n = 0, len(s)
        while i < n:
            j = s.find('#', i)
            length = int(s[i:j])
            out.append(s[j + 1:j + 1 + length])
            i = j + 1 + length
        return out

function encode(strs) {
    let out = '';
    for (const s of strs) {
        out += `${s.length}#${s}`;
    }
    return out;
}

function decode(s) {
    const out = [];
    let i = 0;
    const n = s.length;
    while (i < n) {
        const j = s.indexOf('#', i);
        const len = parseInt(s.slice(i, j), 10);
        out.push(s.slice(j + 1, j + 1 + len));
        i = j + 1 + len;
    }
    return out;
}

class Codec {
    public String encode(List<String> strs) {
        StringBuilder out = new StringBuilder();
        for (String s : strs) {
            out.append(s.length()).append('#').append(s);
        }
        return out.toString();
    }

    public List<String> decode(String s) {
        List<String> out = new ArrayList<>();
        int i = 0, n = s.length();
        while (i < n) {
            int j = s.indexOf('#', i);
            int len = Integer.parseInt(s.substring(i, j));
            out.add(s.substring(j + 1, j + 1 + len));
            i = j + 1 + len;
        }
        return out;
    }
}

function encode(strs: string[]): string {
    let out = '';
    for (const s of strs) {
        out += `${s.length}#${s}`;
    }
    return out;
}

function decode(s: string): string[] {
    const out: string[] = [];
    let i = 0;
    const n = s.length;
    while (i < n) {
        const j = s.indexOf('#', i);
        const len = parseInt(s.slice(i, j), 10);
        out.push(s.slice(j + 1, j + 1 + len));
        i = j + 1 + len;
    }
    return out;
}