Keep the Change

function solve(input){
    var bill = Number(input[0]);
    var mood = input[1];
    switch (mood) {
        case 'happy':
            bill = bill + (bill * 10/100)
            break;
        case 'married':
            bill = bill + (bill * 5/100)
            break;
        //!!!not finished!
        case 'drunk':
            bill = Math.pow((bill * 15 / 100), parseFloat(power))
            break;
        default:
            bill = bill + (bill * 5 / 100)
            break;


    }
    var drunkTip = bill * 15 / 100;
    var power = (drunkTip.toString().charAt(0));

    var tip = bill- Number(input[0]);
    console.log(tip.toFixed(2));
}
solve([
'1230.83',
'drunk'
])