<title>Encodeur/Décodeur Réduction+Indice</title> <style> body { font-family: Arial, sans-serif; padding: 20px; } input, textarea { width: 100%; padding: 5px; margin: 5px 0; } button { padding: 10px 20px; margin: 5px; } </style>

Encodeur/Décodeur Réduction + Indice

<label>Entrez votre phrase :</label>
<input type="text" id="inputText">

<button onclick="coder()">Coder</button>
<button onclick="decoder()">Décoder</button>

<label>Résultat :</label>
<textarea id="output" rows="4" readonly></textarea>

<script>
    // Table des lettres par réduction
    const reductionTable = {
        1: ['A','J','S'],
        2: ['B','K','T'],
        3: ['C','L','U'],
        4: ['D','M','V'],
        5: ['E','N','W'],
        6: ['F','O','X'],
        7: ['G','P','Y'],
        8: ['H','Q','Z'],
        9: ['I','R']
    };

    function removeAccents(text) {
        return text.normalize("NFD").replace(/[\u0300-\u036f]/g, "");
    }

    function coderLettre(letter) {
        letter = letter.toUpperCase();
        for (let red in reductionTable) {
            let idx = reductionTable[red].indexOf(letter);
            if (idx !== -1) return red + (idx + 1);
        }
        return letter; // garde espaces ou ponctuation
    }

    function coder() {
        let text = removeAccents(document.getElementById("inputText").value);
        let coded = Array.from(text).map(c => coderLettre(c));
        document.getElementById("output").value = coded.join("-");
    }

    function decoderCode(code) {
        if (!/^\d\d$/.test(code)) return code; // espace ou ponctuation
        let red = parseInt(code[0]);
        let idx = parseInt(code[1]) - 1;
        if (reductionTable[red] && reductionTable[red][idx]) return reductionTable[red][idx];
        return '?';
    }

    function decoder() {
        let codes = document.getElementById("inputText").value.split("-");
        let decoded = codes.map(c => decoderCode(c)).join("");
        document.getElementById("output").value = decoded;
    }
</script>