First, i gotta say i'm grateful that you take your time for this So i'm 
attempting a Huffman coding simulation from a list of symbol's character 
frequencies from hex file. The result should display all the encoding 
binary of input then write it to the appointed hex file. Thing went 
smoothly for small number like 12 variable (12 numeric values of the 
amount of time that symbol appear aka frequencies). but when i amp that 
number up, say 50 (which i have redeclare in the input file), i 
encounter an simulation error. (i'm using the 32 bit version of modelsim 
altera, some suggest that i may run out of memory, but i'm pretty sure 
i'm far from reaching that)

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** Fatal: (vsim-4) ****** Memory allocation failure. *****

Attempting to allocate 436207632 bytes

Please check your system for available memory and swap space.

Time: 0 ps Iteration: 0 Instance: /testbench/dut/gen[26]/S1 File: 
C:/Users/PC/Desktop/huffman-coding-master/HuffmanEncodingVerilog-master/ 
HuffmanEncodingVerilog-master/Vfiles/shfreg.v  FATAL ERROR while loading 
design

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i change the amount of input by change the value of parameter 
TOTAL_SYMBOLS and parameter ADDR_WIDTH (size of address to account for 
total symbols = log2(TOTAL_SYMBOLS)) and maxhight (assume max hight of 
tree). for instance symbols = 12, addr_width = 4, maxhight = 13 worked, 
but symbols = 50, addr_width = 6, maxhight = 51 don't. i think that the 
problem may lie in my testbench but i don't know where.

my full code is upload in a text file here, feel free to check it out. 
and again, i'm really appreciate your help

https://drive.google.com/file/d/17-_1N-IQvUFdpbAvroTTgc5hC8GRmXDz/view?usp=sharing