Function getWindows

javascript/0042-trapping-rain-water.js:86–94

(height, left, maxLeft, right, maxRight)

const getHeights = (height, left, right) => [height[left], height[right]];

const getWindows = (height, left, maxLeft, right, maxRight) => {
    const [leftHeight, rightHeight] = getHeights(height, left, right);
    const [leftWindow, rightWindow] = [
        maxLeft - leftHeight,
        maxRight - rightHeight,
    ];

    return [leftWindow, rightWindow];
};