我正在做一个多项式计算器，我需要一些帮助，因为我将继续编写代码。
现在我只制作了 polinom 类，我将它表示为带有术语和一些函数的链表（现在只读取和打印多项式函数）。
这是目前只读取多项式并打印它的主程序：
#include "polinom.h"
int main()
{
polinom P1;
bool varStatus = false;
char var = '\0', readStatus = '\0';
cout << "P1 = ";
P1.read(readStatus, var, varStatus); // i don't need readStatus yet as i haven't implemented the reset and quit functions
cout << "\n\nP = ";
P1.print(var);
getch();
return 0;
}
以及头文件polinom.h：
#ifndef _polinom_h
#define _polinom_h
#include <iostream>
#include <list>
#include <cstdlib>
#include <cctype>
#include <cstdio>
#include <conio.h>
using namespace std;
class polinom
{
class term
{
public:
int coef;
int pow;
term()
{
coef = 1;
pow = 0;
}
};
list<term> poly;
list<term>::iterator i;
public:
bool printable(char c)
{
return (
((int(c) > 42 && int(c) < 123) || isspace(c)) && int(c) != 44 && int(c) != 46 && int(c) != 47 &&
int(c) != 58 && int(c) != 59 &&
int(c) != 60 && int(c) != 61 && int(c) != 62 && int(c) != 63 && int(c) != 64 && int(c) != 65 &&
int(c) != 91 && int(c) != 92 && int(c) != 93 && int(c) != 95 && int(c) != 96
);
}
void read(char &readStatus, char &var, bool &varStatus)
{
term t; // term variable to push it into the list of terms
char c, lc, sign; // c = current char, lc = lastchar and sign the '+' or '-' sign before a coefficient
int coef, pow; //variables to pass the coef and power to term t
bool coefRead = false, powRead = false; //reading status of coef and power
while (c != '\r') { //we read characters until carriage return
c = getch(); // get the new imputed char
if (tolower(c) == 'r' || tolower(c) == 'q') { //if the user inputed r or q we reset the input or quit the program
readStatus = c; //pass current char value to readStatus so the program will know what to do next
return; //aborting the reading process
}
else
{
if (printable(c)) cout << c; //print on screen only the correct characters
if (!coefRead && !powRead) //we set term coef to the inputed value
{
if (isdigit(c)) {
if (isdigit(lc)) coef = coef * 10 + int(c); //if the last char was also a digit we multiply the last value of coef by 10 and add current char
else {
if (sign == '-') coef = -(int(c));//if the current coef has '-' before we set coef to it's negative value
else coef = int(c); //this means a new term's coef is read
}
if (!isdigit(c) && isdigit(lc)) coefRead = true; //if the last char was a digit and we reached the var name we stop reading the coefficient
}
else if (coefRead && !powRead) //after coefficient is read we get the term's varname and power
{
if (isdigit(c)) { // just like in the case with coefficient we read the power until the current char is not a digit
if (isdigit(lc)) pow = pow * 10 + int(c);
else pow = int(c);
}
else if (isalpha(c) && isdigit(lc) && !varStatus) { //if the last char was a digit and the current not we reached the var name
var = c; //also even though the variable is inputed more than once we save it only once
varStatus = true; //we mark the var name as read
}
else {
if (isdigit(lc)) powRead = true;
}
}
else {
if (c == '+' || c == '-') { // if a sign was inputed it means a new term is coming and we push the current term to the list and reset
t.coef = coef; // coefRead and powRead so we can read another term
t.pow = pow;
poly.push_back(t);
sign = c;
coefRead = false;
powRead = false;
}
}
lc = c; // we save the last character
}
}
}
void print(char var)
{
for ( i=poly.begin() ; i != poly.end(); i++ ) { //going through the entire list to retrieve the terms and print them
if (i == poly.end() - 1) { // if we reached the last term
if (*(i->pow == 0) //if the last term's power is 0 we print only it's coefficient
cout << *(i->coef);
else
cout << *(i->coef) << var << "^" << *(i->pow); //otherwise we print both
}
else {
if (*(i->coef > 0) //if the coef value is positive
cout << *(i->coef) << var << "^" << *(i->pow) << " + "; //we also add the '+' sign
else
cout << *(i->coef) << var << "^" << *(i->pow) << " - "; // otherwise we add '-' sign
}
}
}
};
#endif
编辑
多亏了 JonH，现在所有的编译错误都得到了修复，但是由于输入字符没有正确插入到列表中，读取功能不起作用。我知道这对你们来说可能微不足道，但如果你能帮助我，那就太好了。
谢谢！