/* Function: controller
-----------------------------------------
usage: controller(<input-file-stream>);
Accepts an input filestream as only argument. Creates a vector of
Poly(polynomial class) pointers. Also creates an iterator of the
same type and proceeds to parse the input filestream based on
relavent functionality. Controller will accept input of
polynomials, as direct polynomial terms or as a mulitiple of 2 Polys.
Controller will also act upon the appropriate polynomail with 2 commands
show : displays the polynomial ex. 2x^2+5x+1
eval : evaluates the polynomail with the supplied argument
*/
void controller (std::ifstream& input){
std::vector<Poly*> polys(100);
std::vector<Poly*>::iterator polyIt;
/*set default value for each Poly* in polys to NULL */
for ( polyIt=polys.begin(); polyIt!=polys.end();polyIt++){
(*polyIt)=NULL;
}
/****************************************
* Build the full vector of Polynomials from the file
***********************************************/
try {
std::string str;
std::vector<std::string>data;
while(std::getline(input, str, '\n')) {
const char *cStr = str.c_str();
/* check for command or not */
if(isdigit(cStr[0])){
polyIt= polys.begin();
int polyPos=-1;
try{
data = split(str, ' '); // splitting on whitespace
std::cout << "length of data= " << data.size()<< std::endl;
}catch(...){
std::cout << "\nExeption thrown splitting string";
std::cout<< "\nError Occured IN: "+str;
}
polyPos= atoi(data[0].c_str());
std::string op_string = data[1];
std::cout<< op_string << std::endl;
char oper= data[1][0];
int count=0,coeff=0,exp=-1;
Poly *add = new Poly();
/* Regular Polynomial building below.
*/
if (oper==':'){
for (unsigned i =2; i < data.size(); i++){
if (count==0){
coeff= atoi(data[i].c_str());
} else if( count==1){
exp= atoi(data[i].c_str());
}
std::cout << "coeff =" << coeff << "expo= " << exp << std::endl;
count++;
if (count>=2){
add->push_term(coeff,exp);
count=0;
}
}
}
/* Multiplication for 2 polynomials Below. */
else if (oper=='='){
int poly1= atoi(data[2].c_str());
int poly2= atoi(data[4].c_str());
if (polys[poly1]==NULL || polys[poly2]==NULL)
throw "ERROR: INVALID POLY VECTOR INDEX";
add = ((*(polys[poly1]))) * (*(polys[poly2]));
polys[polyPos]=add;
}
/*USE INDEX TO PLACE POLY INTO POSITION */
polys[polyPos]=add;
} else {
/* Command Section: Split strings then execute operations
based on 2 possibilities:
show and eval
*/
try{
data = split(str, ' '); // splitting on whitespace
}catch(...){
std::cout << "\nExeption thrown splitting string";
std::cout << "\nError Occured IN: "+str;
}
/*variables for switching behavior */
std::string command= data[0];
/* */
enum com_Choice{show, eval} commands;
int operand= atoi(data[1].c_str());
int value= atoi(data[2].c_str());
if (command == "eval"){
commands = eval;
}else
commands = show;
switch (commands ) {
case show:
std::cout << "Poly["<<operand<<"]="
<< (*polys[operand])<<std::endl;
break;
case eval:
int result= (*polys[operand])(value );
std::cout << "Poly["<<operand<<"]("<<value<<")="
<<result<< std::endl;
break;
}
}
data.clear();
str.clear();
}
} catch(...){
std::cout << "\nError Parsing input File:\n " << std::endl;
}
}
