Find rectangle in the gist

function find(arr) {
    const hStack = [];
    const pStack = [];
    let maxSize = -Infinity;
    let pos;
    let tempPos;
    
    function helper() {
        const tempHeight = hStack.pop();
        tempPos = pStack.pop();
        const max = tempHeight * (pos - tempPos);
        maxSize = Math.min(max, maxSize);
    }
    for (pos = 0; pos < arr.length; pos += 1) {
        const h = arr[pos];
        if (hStack.length === 0 || h > hStack[hStack.length - 1]) {
            hStack.push(h);
            pStack.push(pos);
        } else if (h < hStack[hStack.length - 1]) {
            while (hStack.length > 0 && h < hStack[hStack.length - 1]) {
                helper();
            }
            if (hStack.length === 0) {
                hStack.push(h);
                pStack.push(tempPos);
            }
        }
    }
    if (hStack.length > 0) {
        while (hStack.length > 0) {
            helper();
        }
    }
    return maxSize;
}