数据结构阶段二(3)

本次完成了含有一个未知数的计算，还修复了好多bug（比如计算负数时报错）

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#include<iostream>
#include<string>
using namespace std;

// 链栈的存储结构
typedef struct StackNode
{
	string date;
	struct StackNode* next;
} StackNode, * LinkStack;

// 链栈的初始化
int InitStack(LinkStack& S)
{
	S = NULL;  //将栈顶指针置空
	return 1;
}


int Push(LinkStack& S, string e) {
	LinkStack p;
	p = new StackNode;
	if (!p)
		exit(0);
	p->date = e;
	p->next = S;
	S = p;
	return 0;
}

//出栈
int Pop(LinkStack& S, string& e) {
	LinkStack p;
	p = new StackNode;
	if (S == NULL)
		return 1;
	e = S->date;
	p = S;
	S = S->next;
	delete p;
	return 0;
}

int Linklength(LinkStack S)
{
	int num = 0;
	LinkStack q = S;
	while (q) {
		num++;
		q = q->next;
	}
	return num;
}

void countAB(string num1, string num2, int& A, int& B, int& num_2) {
	//Ax+B
	int i;
	num_2 = atoi(num2.c_str());
	char num1_1[1000];
	strcpy(num1_1, num1.c_str());
	int len = strlen(num1_1);
	for (i = 0; i < len; i++) {
		if (num1_1[i] == 'x') {
			break;
		}
	}
	if (i == 0) {
		A = 1;
	}
	if (i == len - 1) {
		B = 0;
	}
	if (i != 0 || i != len - 1) {
		if (num1_1[0] == '-' && i == 1) {
			A = -1;
		}
		else if (num1_1[0] == '-' && i != 1) {
			int j = 1;
			char* A1 = &num1_1[j];
			while (true)
			{
				if (num1_1[j + 1] >= '0' && num1_1[j + 1] <= '9') {
					A1 = strcat(A1, &num1_1[j + 1]);
					j++;
				}
				else
				{
					break;
				}
			}
			A = atoi(A1);
			A = -A;
		}
		else {
			int j = 0;
			string A1(1, num1_1[j]);
			while (true)
			{
				if (j < len && num1_1[j + 1] >= '0' && num1_1[j + 1] <= '9') {
					string A2(1, num1_1[j + 1]);
					A1 = A1 + A2;
					j++;
				}
				else
				{
					break;
				}
			}
			A = atoi(A1.c_str());
		}
		//计算出B
		int j = i + 2;
		char* B1 = &num1_1[j];
		while (true)
		{
			if (num1_1[j + 1] >= '0' && num1_1[j + 1] <= '9') {
				B1 = strcat(B1, &num1_1[j + 1]);
				j++;
			}
			else
			{
				break;
			}
		}
		B = atoi(B1);
		if (num1_1[i + 1] == '-') {
			B = -B;
		}
		if (num1_1[0] == 'x') {
			A = 1;
		}
		if (num1_1[len - 1] == 'x') {
			B = 0;
		}
	}
}
string wuX(string num1, string num2, string oper) {
	int num_1, num_2, mid1;
	string mid;
	num_1 = atoi(num1.c_str());
	num_2 = atoi(num2.c_str());
	//开始计算最优先的lisp子表达式
	if (oper.compare("+") == 0) {
		mid1 = num_1 + num_2;
		mid = to_string(mid1);
	}
	else if (oper.compare("-") == 0) {
		mid1 = num_2 - num_1;
		mid = to_string(mid1);
	}
	else if (oper.compare("*") == 0) {
		mid1 = num_1 * num_2;
		mid = to_string(mid1);
	}
	else if (oper.compare("/") == 0) {
		mid1 = num_2 / num_1;
		mid = to_string(mid1);
	}
	else
	{
		printf("表达式有误（不识别的运算符）");
		return false;
	}
	return mid;
}

string youX(string num1, string num2, string oper) {
	//Ax+B
	string mid,A_1,B_1;
	int A, B, num_2;
	int i;
	countAB(num1, num2, A, B, num_2);
	//多项式计算
	if (oper.compare("+") == 0) {
		B = B + num_2;
		A_1 = to_string(A);
		B_1 = to_string(B);
		if (A != 0 && B < 0) {
			mid = A_1 + "x" + B_1;
			if (A == 1) {
				mid = "x" + B_1;
			}
		}
		else if (A != 0 && B > 0) {
			mid = A_1 + "x" + "+" + B_1;
			if (A == 1) {
				mid = "x+" + B_1;
			}
		}
		else if (A != 0 && B == 0) {
			mid = A_1 + "x";
			if (A == 1) {
				mid = "x";
			}
		}
		else if (A == 0) {
			mid = B_1;
		}
	}
	//常数-含x
	else if (oper.compare("-") == 0) {
		B = num_2 - B;
		A_1 = to_string(A);
		B_1 = to_string(B);
		if (A != 0 && B < 0) {
			if (A > 0) {
				mid = "-" + A_1 + "x" + B_1;
				if (A == 1) {
					mid = "x" + B_1;
				}
			}
			else {
				A_1 = to_string(-A);
				mid = A_1 + "x" + B_1;
			}
		}
		else if (A != 0 && B > 0) {
			if (A > 0) {
				mid = "-" + A_1 + "x" + "+" + B_1;
				if (A == 1) {
					mid = "x+" + B_1;
				}
			}
			else {
				A_1 = to_string(-A);
				mid = A_1 + "x" + "+" + B_1;
			}
		}
		else if (A != 0 && B == 0) {
			if (A > 0) {
				mid = "-" + A_1 + "x";
				if (A == 1) {
					mid = "x";
				}
			}
			else {
				A_1 = to_string(-A);
				mid = A_1 + "x";
			}
		}
		else if (A == 0) {
			mid = B_1;
		}
	}
	else if (oper.compare("*") == 0) {
		A = A * num_2;
		B = B * num_2;
		A_1 = to_string(A);
		B_1 = to_string(B);
		if (A != 0 && B < 0) {
			mid = A_1 + "x" + B_1;
			if (A == 1) {
				mid = "x" + B_1;
			}
		}
		else if (A != 0 && B > 0) {
			mid = A_1 + "x+" + B_1;
			if (A == 1) {
				mid = "x+" + B_1;
			}
		}
		else if (A != 0 && B == 0) {
			mid = A_1 + "x";
			if (A == 1) {
				mid = "x";
			}
		}
		else if (A == 0) {
			mid = B_1;
		}
	}
	else if (oper.compare("/") == 0) {
		printf("x的系数不为1，不能计算");
		return false;
	}
	else
	{
		printf("表达式有误（不识别的运算符）");
		return false;
	}
	return mid;
}

string chufa(string num1, string num2, string oper) {
	//Ax+B
	string mid, A_1, B_1;
	double A1, B1;
	int A, B, num_2;
	countAB(num1, num2, A, B, num_2);
	A1 = (double)A / (double)num_2;
	B1 = (double)B / (double)num_2;
	A_1 = to_string(A1);
	B_1 = to_string(B1);
	if (A != 0 && B < 0) {
		mid = A_1 + "x" + B_1;
		if (A == 1) {
			mid = "x" + B_1;
		}
	}
	else if (A != 0 && B > 0) {
		mid = A_1 + "x+" + B_1;
		if (A == 1) {
			mid = "x+" + B_1;
		}
	}
	else if (A != 0 && B == 0) {
		mid = A_1 + "x";
		if (A == 1) {
			mid = "x";
		}
	}
	else if (A == 0) {
		mid = B_1;
	}
	return mid;
}

string jianfa(string num1, string num2, string oper) {
	string mid, A_1, B_1;
	int A, B, num_2;
	countAB(num1, num2, A, B, num_2);
	B = B - num_2;
	A_1 = to_string(A);
	B_1 = to_string(B);
	if (A != 0 && B != 0) {
		mid = A_1 + "x" + B_1;
		if (A == 1) {
			mid = "x" + B_1;
		}
	}
	else if (A != 0 && B == 0) {
		mid = A_1 + "x";
		if (A == 1) {
			mid = "x";
		}
	}
	else if (A == 0) {
		mid = B_1;
	}
	return mid;
}

int count(LinkStack &numStack, LinkStack& operStack, string &mid) {
	int length1 = Linklength(numStack);
	int length2 = Linklength(operStack);
	string num1, num2, oper;
	if (length1 <= 1 || length2 == 0) {
		cout << "error" << endl;
	}
	else
	{
		Pop(numStack, num1);
		Pop(numStack, num2);
		Pop(operStack, oper);
		if (num1.find("x") == string::npos && num2.find("x") == string::npos) {
			mid = wuX(num1, num2, oper);
		}
		if (num2.find("x") != string::npos && num1.find("x") == string::npos) {
			if (oper.compare("/") == 0) {
				//前一个数有x
				mid = chufa(num2, num1, oper);
			}
			else if (oper.compare("-") == 0) {
				//前一个数有x
				mid = jianfa(num2, num1, oper);
			}
			else
			{
				mid = youX(num2, num1, oper);
			}
		}
		if (num1.find("x") != string::npos && num2.find("x") == string::npos) {
			mid = youX(num1, num2, oper);
		}
	}
}


int main() {
	LinkStack numStack, operStack;
	InitStack(numStack);
	InitStack(operStack);
	string mid;
	char str[200];
	gets_s(str);
	if (str[0] == '0') {
		exit(0);
	}
	int length = strlen(str);
	int flag = 0;//0表示正，1表示负
	for (int i = 0; i < length; i++) {
		if (str[length - 1] != ')') {
			cout << "error" << endl;
			break;
		}
		if (str[i] == '+' || str[i] == '-' || str[i] == '*' || str[i] == '/')
		{
			string str(1, str[i]);
			Push(operStack, str);
		}
		else if (str[i] == '(' || str[i] == ',')
		{
			if (str[i + 1] == '-' && str[i + 2] != '(') {
				i++;
				flag = 1;
			}
		}
		else if (str[i] == ')')
		{
			count(numStack, operStack, mid);
			int length1 = Linklength(numStack);
			int length2 = Linklength(operStack);
			if (length1 <= 1 && length2 == 0) {
				cout << mid << endl;
			}
			else if (i == length - 1) {
				cout << "error" << endl;
				break;
			}
			else {
				Push(numStack, mid);
			}
		}
		else if (str[i] >= '0' && str[i] <= '9') {
			string str1(1, str[i]);
			while (true)
			{
				if (str[i + 1] >= '0' && str[i + 1] <= '9') {
					string str2(1, str[i + 1]);
					str1 = str1 + str2;
					i++;
				}
				else
				{
					break;
				}
			}
			if (flag == 1) {
				str1 = "-" + str1;
				flag = 0;
			}
			Push(numStack, str1);
		}
		else if (str[i] == 'x') {
			string str1(1, str[i]);
			int j = i;
			while (true)
			{
				if (str[j - 1] != ',' && str[j - 1] != '(') {
					string str2(1, str[j - 1]);
					str1 = str2 + str1;
					j--;
				}
				else
				{
					break;
				}
			}
			while (true)
			{
				if (str[i + 1] != ',' && str[i + 1] != ')') {
					string str2(1, str[i + 1]);
					str1 = str1 + str2;
					i++;
				}
				else
				{
					break;
				}
			}
			if (flag == 1) {
				str1 = "-" + str1;
				flag = 0;
			}
			Push(numStack, str1);
		}
		else
		{
			cout << "error" << endl;
			break;
		}
	}
}