/*
    Copyright (C) 2019 Alessandro Languasco
*/

 /****************   	A. LANGUASCO  		******************** 
************* COMPUTATION OF THE EULER KRONECKER CONSTANTS MOD q(PRIME) *******/
 
 
 /*****************   Precomputations for the external C program   ****************/
 \\ \p needed to decide the precision  default (format, f)  for the floating point 
 
{mainEK(q)= local(g, g1, minutes, millisec, seconds, elaptimeprecomp,
prootfile); 

default(format , f);  \\ print numbers with floating point notation (not E notation)

if (!isprime(q) || q==2, print("****** error: q has to be an odd prime ******");return); 

/* initialization */ 
 
prootfile = fileopen("./primroot.res", "w");
filewrite(prootfile,q);

gettime();

print("Computing the primitive root for q = ",q, " and saving on file");
g1=znprimroot(q);  	
g=lift(g1);   

elaptimeprecomp=gettime();
	
filewrite(prootfile,g);
fileclose(prootfile);

/* print computation time */
seconds=floor(elaptimeprecomp/1000)%60;
minutes=floor(elaptimeprecomp/60000);
millisec=elaptimeprecomp- minutes*60000 - seconds*1000;
\\print(elaptimeprecomp); 
print("Primitive root generation time: ", minutes, " min, ", seconds, " sec, ", millisec, " millisec");	

print("******************************************");

print("Now you can call the precomputation programs");

print("******************************************");
} 
 
/************************************  
  
*******/