Dz2.3

/*построить дерево бинарного разбора выражения (f+1)*(6/(1+g)+4) */
#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <string.h>
#include <time.h>
#include <stdlib.h>
using namespace std;

struct Btree
{
	char data[10];
	Btree* left;
	Btree* right;
};

int priority(char c) //функция определяет приоритет операции или возвращает -1 если это число
{
	switch (c)
	{
	case'+':
	case'-':
		return 1;

	case'*':
	case'/':
		return 2;
	}
	return 100;
}

void PrintTree(Btree* tree, int space)
{
	const int COUNT = 5;
	if (tree != NULL)
	{
		space += COUNT;
		PrintTree(tree->right, space);
		for (int i = COUNT; i < space; i++)
			printf("%c", ' ');
		printf_s("%s\n", tree->data);
		PrintTree(tree->left, space);
	}
}
int its_a_number(Btree* tree)
{
	int i = 0;
	if (!tree) return 0;
	while (tree->data[i])
		if (!strchr("-0123456789", tree->data[i++]))
			return 0;
	return 1;
}
void calculate(Btree* tree)
{
	while (tree->left->left != NULL && tree->left != NULL)
		calculate(tree->left);
	while (tree->right->right != NULL && tree->right != NULL)
		calculate(tree->right);
	int a, b, c = 0;
	if (!tree || !its_a_number(tree->left) || !its_a_number(tree->right)) return;
	a = atoi(tree->left->data);
	b = atoi(tree->right->data);
	switch (tree->data[0])
	{
	case'+':c = a + b; break;
	case'-':c = a - b; break;
	case'*':c = a * b; break;
	case'/':c = a / b; break;
	}
	free(tree->left);
	free(tree->right);
	sprintf(tree->data, "%d", c);
	cout << c << endl;
	tree->left = NULL;
	tree->right = NULL;
}
Btree* let_it_tree(char term[], int first, int last)
{
	Btree* tree = (Btree*)malloc(sizeof(Btree));
	char c;
	int min, i, k, prt;
	int nest = 0;
	if (first == last || first == (last - 1))
	{
		tree->data[0] = term[first];
		tree->data[1] = '\0';
		tree->left = NULL;
		tree->right = NULL;
		return tree;
	}
	min = 100;
	for (i = first; i < last; i++)
	{
		c = term[i];
		if (c == '(') { nest++; continue; }
		if (c == ')') { nest--; continue; }
		if (nest > 0) continue;
		prt = priority(c);
		if (prt <= min)
		{
			min = prt;
			k = i;
		}
	}
	if (min == 100 && term[first] == '(' && (term[last] == ')' || term[last] == '\0'))
		return let_it_tree(term, first + 1, last - 1);
	else
	{
		tree->data[0] = term[k];
		tree->data[1] = '\0';
		tree->left = let_it_tree(term, first, k - 1);
		tree->right = let_it_tree(term, k + 1, last);
		return tree;
	}
}
void genrand(int* x)
{

	for (int i = 0; i < 10; i++)
	{
		x[i] = rand() % 15;
		cout.width(5);
		cout<< x[i];
	}
	cout<< endl;
}
void Tree2(Btree* r, int n, int m)//обратный
{
	if (r != NULL)
	{
		Tree2(r->left, n, m);
		if (r->data[0] == 'a')
		{
			sprintf(r->data, "%d", n);
		}
		if (r->data[0] == 'b')
		{
			sprintf(r->data, "%d", m);
		}
		Tree2(r->right, n, m);
	}
}
int main()
{
	srand(time(NULL));
	int* n = (int*)malloc(10 * sizeof(int));
	int* m = (int*)malloc(10 * sizeof(int));
	Btree* tree = (Btree*)malloc(sizeof(Btree));
	char* term = (char*)malloc(30 * sizeof(char));
	cout << "Input your fucntion" << endl;
	cin>> term;
	tree = let_it_tree(term, 0, strlen(term));
	PrintTree(tree, 10);
	cout<< "n is ";
	genrand(n);
	cout<< "m is ";
	n[0] = 7;
	genrand(m);
	Tree2(tree, n[0], m[0]);
	PrintTree(tree, 10);
	cout<< "result is "<< endl;
	calculate(tree);
}