/* roll.cpp
Program to simulate arbitrary dice roll.
Written by David B. Wofford
Restarted 9-29-2004 (Stupid hard drive format)
V1.0 finished 10-18-2004 :D
*/

#include <iostream>
#include <string>
#include <ctime>
#include <cstring>

using namespace std;

void usage(void)
{ cout<<"roll nds[+c]\nn=number of dice\ns=number of sides\n"<<
            "c=constant [Optional, +-c required for negative c]"<<endl;
}

void error(void)
{ cout<<"Invalid use"<<endl<<"Correct usage:"<<endl;
   usage();
   exit(1);
}

int main (int argc, char ** argv)
{ int n,s,c=0,t=0;
   srand(time(NULL));
   if (argc==1)
        error();
   if (strcmp(argv[1],"--help")==0||strcmp(argv[1],"-h")==0)
        { usage();
           return 0;
        }
   string tok="";
   for (int i=1;i<argc;i++)
        tok=tok+argv[i];
   char* st;
   st=strtok(&tok[0],"d \t\n");
   if(st==NULL)
        error();
   n=atoi(st);
   st=strtok(NULL," +\t\n");
   s=atoi(st);
   if(st==NULL)
        error();
   if (n==0||s==0)
        error();
   for (int i=0;i<n;i++)
        t+=(rand()%s)+1;
   cout<<t;
   st=strtok(NULL,"");
   if(st!=NULL)
        c=atoi(st);
   if (c!=0)
        cout<<"+"<<c<<"="<<t+c;
   cout<<endl;
   return 0;
}