function validateInputBt(inputElement, min, max) {
    const value = parseFloat(inputElement.value);
    if (value < min || value > max) {
        alert(`The value must be a number between ${min} y ${max}.`);
        inputElement.value = ''; 
    }
}

function factorial(n) {
    if (n === 0 || n === 1) {
        return 1;
    }
    let result = 1;
    for (let i = 2; i <= n; i++) {
        result *= i;
    }
    return result;
}

function binomialProbability() {
    const totBt = parseInt(document.getElementById("totBt").value);
    const pattBt = parseInt(document.getElementById("pattBt").value);
    const avgBt = parseFloat(document.getElementById("avgBt").value);

    if (isNaN(totBt) || isNaN(pattBt) || isNaN(avgBt) || totBt < 0 || pattBt < 0 || avgBt < 0) {
        document.getElementById("probBt").textContent = "0.0";
        return;
    }

    const p = avgBt / 100; 
    let probability = 0;

    for (let k = 0; k < pattBt; k++) {
        const coefficient = factorial(totBt) / (factorial(k) * factorial(totBt - k));
        const term = coefficient * Math.pow(p, k) * Math.pow(1 - p, totBt - k);
        probability += term;
    }

    document.getElementById("probBt").textContent = ((1 - probability) * 100).toFixed(2); 
}

const totBt = document.getElementById('totBt');
const pattBt = document.getElementById('pattBt');
const avgBt = document.getElementById('avgBt');

const totalMin = 1, totalMax = 170; 
const patternMin = 0, patternMax = 170; 
const avgMin = 0, avgMax = 100; 

totBt.addEventListener('input', () => validateInputBt(totBt, totalMin, totalMax));
pattBt.addEventListener('input', () => validateInputBt(pattBt, patternMin, patternMax));
avgBt.addEventListener('input', () => validateInputBt(avgBt, avgMin, avgMax));