Create a program to demonstrate a basic bin packing algorithm using vectors:

$1.$ We generate a random number of bins $(1-10)$ and assign random capacities $(10-50)$ to

each bin.

$2.$ We generate a random number of containers $(5-20)$ with random sizes. The maximum

container size is limited to the largest bin capacity.

$3.$ The bin packing algorithm tries to pack each container into existing bins. If it doesn't fit,

it opens a new bin.

$4.$ We use vector$>$ to represent packed bins. Each inner vector represents a

bin, with the first element being the remaining capacity and subsequent elements being

the packed container sizes.

$5.$ The algorithm prioritizes using existing bins before opening new ones.

$6.$ If a container can't be packed into any available bin, it prints a message indicating so$.$

$7.$ Finally, we print the contents of each packed bin and list any unused bins.

This implementation demonstrates the use of vectors for both the bins and containers, as well

as for storing the packed results.