Grocery Store Micromanagement

Question

You are an employee at the hip new grocery store Half Foods, and it's the day before Thanksgiving Christmas Easter. Since the store will be packed with customers rushing to get their foodstuffs, the store needs a traffic manager to send everyone to the appropriate lines. Being lazy, you'd like to automate this so that you can go hit the deli before everyone takes all the turkey ham whatever. However, all you have with you is your phone, and coding long programs on it is a real pain -- so you need to bust out your ninja code-golf skills.

Challenge

Let's visualize the grocery store on a two-dimensional grid. Here's a sample grid to dissect:

                             e
                             s
                             s
                             s
                               Y

#           #                #s           #
#s          #                #s           #
#s          #                #s           #
#s          #s               #s           #
#3          #1               #4           #
 x           x                x            x

The grid starts out with an e, which represents an "outlet" to the rest of the store. Every generation, all of the outlets in the grid spawn a shopper (s) directly below. The shoppers move downward each generation until they reach you (Y). When a shopper reaches the same row as you, you must teleport the shopper to the beginning of the line with the least amount of shoppers in it. A shopper immediately moves to the line when they would move into the row with the Y, there is no generation in between. The lines are represented by the #s -- the column after the #s is a line. The shoppers go down to the end of the line (represented by an exit x), and then turn into a random number between 1 and 5. Each generation, you must decrement numbered shoppers by 1 -- when a shopper would reach 0, they're done checking out and they leave the store.

Given an input of a grid like this, output the next generation of the grocery store (move all the shoppers down simultaneously, redirect shoppers, and have them leave if they are done).

Samples

Input:

                e
                 
                     Y


#           #                #            #
#           #                #            #
#           #                #            #
#           #                #            #
#           #                #            #
 x           x                x            x

Output:

                e
                s 
                     Y


#           #                #            #
#           #                #            #
#           #                #            #
#           #                #            #
#           #                #            #
 x           x                x            x

Input:

                e
                s 
                     Y


#           #                #            #
#           #                #            #
#           #                #            #
#           #                #            #
#           #                #            #
 x           x                x            x

Output

                e
                s 
                     Y


#s          #                #            #
#           #                #            #
#           #                #            #
#           #                #            #
#           #                #            #
 x           x                x            x

Input:

                e
                 
                     Y


#           #                #            #
#           #                #            #
#           #                #            #
#s          #                #            #
#           #                #            #
 x           x                x            x

(Possible) Output:

                e
                s 
                     Y


#           #                #            #
#           #                #            #
#           #                #            #
#           #                #            #
#3          #                #            #
 x           x                x            x

Input:

                e
                s 
                     Y


#           #                #            #
#           #                #            #
#           #                #            #
#           #                #            #
#3          #                #            #
 x           x                x            x

Output:

                e
                s 
                     Y


#           #s               #            #
#           #                #            #
#           #                #            #
#           #                #            #
#2          #                #            #
 x           x                x            x

Input:

                e
                 
                     Y


#           #                #            #
#           #                #            #
#           #                #            #
#           #                #            #
#1          #                #            #
 x           x                x            x

Output:

                e
                s 
                     Y


#           #                #            #
#           #                #            #
#           #                #            #
#           #                #            #
#           #                #            #
 x           x                x            x

This is code-golf, so shortest code wins.

Answer 1

Python 2, 477 463 453 449 423 402 397 396 393 bytes

t=input()
e=enumerate
q,r=" s"
for i,L in list(e(t))[:0:-1]:
 for j,c in e(L):
	a=t[i-1][j]
	if"0"<c<"6":L[j]="0 1234"[int(c)]
	if(r==a)*q==L[j]:t[i-1][j],L[j]=q+r
	if"e"==a:L[j]=r
	if r==L[j]and"x"==t[i+1][j]:L[j]="5"
 if"Y"in L:x=L.count(r);t[i]=[p.replace(r,q)for p in L]
for i,l in list(e(t))[::-1]:
 for j,c in e(l):
	if"#"==c and(q==l[j+1])*x:x-=1;l[j+1]=r
print"\n".join(map("".join,t))

Try it online!

Still working on golfing this but it solves the problem for now

Answer 2

C++, 898 896 885 841 bytes

Very long to code... but it's there

-2 bytes thanks to Conor O'Brien
-45 byte thanks to Zacharý

#include<vector>
#include<string>
#include<algorithm>
#include<ctime>
#define B begin()
#define L length()
#define C(e)if(i[j].find(e)!=string::npos&&!
#define S's'
#define T size()
#define U i[x][a]
using namespace std;auto g=[](auto&i){int e=i[0].find('e'),n=0,y=0,h=0,o,j,c,x,t=0;for(auto&a:i)t=a.L>t?a.L:t;for_each(i.B,i.end(),[&i,t](string&s){s.resize(t);});srand(time(0));vector<int>s,l;for(j=0;j<i.T;++j){C(S)y)++n;C(89)0)y=j;C(35)h){h=j;for(int d=0;d<i[j].T;++d)if(i[j][d]==35)l.push_back(d+1);s.resize(l.T);}if(h)for(c=0;c<l.T;c++)if(i[j][l[c]]!=32)++s[c];C('x')0)x=j;}--x;for_each(l.B,l.end(),[&i,&x,h](int&a){if(U!=32)--U;if(U==10)U=32;for(int b=x;b>h;--b){if(i[b][a]==32&&i[b-1][a]==S){i[b][a]=S;i[b-1][a]=32;}}if(U==S)U=49+rand()%5;});if(i[y-1][e]==S)i[h][l[min_element(s.B,s.end())-s.B]]=S;for(j=1;j<n+2;++j)if(j<y)i[j][e]=S;};

So... some details :

• You have to pass a std::vector<std::string> ( they will be resized at the same length the longest string is )

• All lines of # starts at the same y ( vertical ) coordinates, are the same length, and end at the same y ( vertical ) coordinates

• Assume that the grid have at least 1 # line or more, have one letter e ( one outlet ) at the top, one letter Y

• Assume that the input is a valid output so the shoppers waiting to be redirected will always be one after another

Edit : Just saw in the comments of Wheat Wizard's answer that it should support multiple entrances, i will continue to work on that