Revise paste Untitled C#

#include <iostream>
#include <string>
#include <fstream>
using namespace std;
struct var {
	string name;
	string n;
};
struct node {
	var info;
	node* next;
};
void add(node*& head, var n) {
	node* q = new node;
	q->next = NULL;
	q->info = n;
	if (head == NULL) {
		head = q;
	}
	else {
		node* p = head;
		while (p->next != NULL) {
			p = p->next;
		}
		p->next = q;
	}
}
void ch(node*& head, var n) {
	node* p = head;
	bool b = false;
	while (p && !b) {
		if (p->info.name == n.name) {
			p->info.n = n.n;
			b = true;
		}
		p = p->next;
	}
	if (!b)
		add(head, n);
}
string find(string& name, node*& head) {
	node* p = head;
	while (p) {
		if (p->info.name == name) {
			return p->info.n;
		}
	}
	return "-";
}
int defop(char g) {
	switch (g) {
	case '|': // диз
		return 0;
		break;
	case '&': // кон
		return 1;
		break;
	case '+': // слож
		return 2;
		break;
	case '-': // имп
		return 3;
		break;
	case '*': // шеф
		return 4;
		break;
	case ';':
		return 5;
		break;
	case ' ':
		return 5;
		break;
	default:
		return -1;
	}
}
bool f(node*& vars) {
	ifstream in("in.txt");
	int condition = 0;
	int op = 0;
	char c;
	string name;
	int idxname = 0;
	string n;
	int idxn = 0;
	string n1;
	int idxn1 = 0;
	string name1;
	while (in >> c) {
		switch (condition) {
		case 0:
			if (isdigit(c) || isalpha(c)) {
				if (idxname == 0 && isdigit(c))
					condition = -1;
				else {
					name += c;
				}
			}
			else if (c == ':')
				condition = 1;
			else
				condition = -1;
			break;
		case 1:
			if (c == '=')
				condition = 1;
			else if (isalpha(c)) {
				condition = 2;
				name1 = c;
			}
			else if (c == '0' || c == '1') {
				condition = 3;
				idxn = 1;
				n = c;
			}
			else
				condition = -1;
			break;
		case 2:
			if (isalpha(c) || isdigit(c)) {
				name1 += c;
			}
			else if (c == ' ' || c == ';') {
				n = find(name1, vars);
				if (n == "-") 
					condition = -1;
				else {
					var t;
					t.n = n;
					t.name = name;
					name = "";
					idxname = 0;
					ch(vars, t);
					condition = 0;
				}
			}
			else {
				op = defop(c);
				if (op == -1)
					condition = -1;
				else
					condition = 4;
			}
			break;
		case 3:
			if (idxn < 8) {
				if (c == '0' || c == '1') {
					idxn++;
					n += c;
				}
				else
					condition = -1;
			}
			else {
				if (c == '0' || c == '1')
					condition = -1;
				else {
					op = defop(c);
					if (op == -1)
						condition = -1;
					else if (op == 5) {
						var t;
						t.n = n;
						t.name = name;
						name = "";
						idxname = 0;
						ch(vars, t);
						condition = 0;
					}
					else
						condition = 4;
				}
			}
			break;
		case 4:
			if (isalpha(c)) {
				condition = 5;
				name1 = c;
			}
			else if (c == '0' || c == '1') {
				condition = 6;
				idxn1 = 1;
				n1 = c;
			}
			else
				condition = -1;
			break;
		case 5:
			if (isalpha(c) || isdigit(c)) {
				name1 += c;
			}
			else if (c == ' ' || c == ';') {
				n1 = find(name1, vars);
				if (n1 == "-")
					condition = -1;
				else {
					string ans = "00000000";
					for (int i = 0; i < 8; ++i) {
						int a = (n[i] - '0'), b = (n1[i] - '0');
						switch (op) {
						case 0:
							ans[i] = (a || b) + '0';
							break;
						case 1:
							ans[i] = (a && b) + '0';
							break;
						case 2:
							ans[i] = ((a + b) % 2) + '0';
							break;
						case 3:
							ans[i] = (!(a && !b)) + '0';
							break;
						case 4:
							ans[i] = (!(a && b)) + '0';
							break;
						}
					}
					var gh;
					gh.n = ans;
					gh.name = name;
					name = "";
					idxname = 0;
					ch(vars, gh);
					condition = 0;
				}
			}
			else
				condition = -1;
			break;
		case 6:
			if (idxn1 < 8) {
				if (c == '0' || c == '1') {
					idxn1++;
					n1 += c;
				}
				else
					condition = -1;
			}
			else {
				if (c == '0' || c == '1')
					condition = -1;
				else {
					string ans = "00000000";
					for (int i = 0; i < 8; ++i) {
						int a = (n[i] - '0'), b = (n1[i] - '0');
						switch (op) {
						case 0:
							ans[i] = (a || b) + '0';
							break;
						case 1:
							ans[i] = (a && b) + '0';
							break;
						case 2:
							ans[i] = ((a + b) % 2) + '0';
							break;
						case 3:
							ans[i] = (!(a && !b)) + '0';
							break;
						case 4:
							ans[i] = (!(a && b)) + '0';
							break;
						}
					}
					var gh;
					gh.n = ans;
					gh.name = name;
					name = "";
					idxname = 0;
					ch(vars, gh);
					condition = 0;
				}
			}
		}
		if (condition == -1)
			return false;
	}
	return true;
}
void pr(node* head) {
	while (head) {
		cout << head->info.name << '=' << head->info.n << '\n';
		head = head->next;
	}
}
int main()
{
	node* vars = NULL;
	if (f(vars)) {
		pr(vars);
	}
	else {
		cout << "syntax error";
	}
}