Пример #1
0
int comput(const char *exp) {
	int i = 0;
	int ret;
	LinkStack *stack = LinkStack_Create();
	
	for (i=0; exp[i] != '\0'; i++) {
		if ( isNumber(exp[i]) )	
			LinkStack_Push(stack, (void*)value(exp[i]));
		else if ( isOperator(exp[i]) ) {
			int right = (int)LinkStack_Pop(stack);
			int left  = (int)LinkStack_Pop(stack);
			ret = express(left, right, exp[i]);
			LinkStack_Push(stack, (void*)ret);
		} else {
			break;
		}
	}

	if ( LinkStack_Size(stack)==1 && exp[i]=='\0')
		ret = (int)LinkStack_Pop(stack);
	else
		printf("invalid expression!\n");

	LinkStack_Destroy(stack);
	return ret;
}
Пример #2
0
void tranform(const char * exp) {
	int i = 0;
	LinkStack * stack = LinkStack_Create();
	
	while ( exp[i] != '\0' ) {
		if ( isNumber(exp[i]) )
			print(exp[i]);
		else if ( isOperator(exp[i]) ) {
			while (priority(exp[i]) <= 
				priority((char)(int)LinkStack_Top(stack)) ) {
				print((char)(int)LinkStack_Pop(stack));
			}
			LinkStack_Push(stack, (void*)(int)exp[i]);
		} else if ( isLeft(exp[i]) ) {
			LinkStack_Push(stack, (void*)(int)exp[i]);
		} else if ( isRight(exp[i]) ) {
			char c = 0;
			while ((c=(char)(int)LinkStack_Pop(stack)) != '(')
				print(c);
		} else {
			printf("invalid expression!\n");
			break;
		}
		i++;
	}
	
	while ( LinkStack_Size(stack)>0 && exp[i]=='\0')
		print((char)(int)LinkStack_Pop(stack));
	
	LinkStack_Destroy(stack);
}
Пример #3
0
int scanner(const char *code)
{
	int i = 0;
	int ret = 0;
	LinkStack *stack = LinkStack_Create();

	while ( code[i] != '\0') {
		if ( isLeft(code[i]) )
			LinkStack_Push(stack, (void*)(code+i));
		if ( isRight(code[i]) ) {
			char* c = (char*)LinkStack_Pop(stack);
			if ( (c==NULL) || !match(*c, code[i]) ) {
				printf("%c does not match!\n", code[i]);
				ret = 0;
				break;
			}
		}

		i++;
	}

	if ( LinkStack_Size(stack)==0 && code[i]=='\0') {
		printf("success!\n");
		ret = 1;
	} else {
		printf("failed!\n");
		ret = 0;
	}
	
	LinkStack_Destroy(stack);
	return ret;
}
Пример #4
0
int compute(const char* exp)
{
	LinkStack* stack = LinkStack_Create();
	int ret = 0;
	int i = 0;

	while (exp[i] != '\0')
	{
		if (isNumber3(exp[i]))
		{
			LinkStack_Push(stack, (void*)value(exp[i]));
		}
		else if (isOperator3(exp[i]))
		{
			int right = (int)LinkStack_Pop(stack);
			int left = (int)LinkStack_Pop(stack);
			int result = express(left, right, exp[i]);

			LinkStack_Push(stack, (void*)result);
		}
		else
		{
			printf("Invalid expression!");
			break;
		}

		i++;
	}

	if ((LinkStack_Size(stack) == 1) && (exp[i] == '\0'))
	{
		ret = (int)LinkStack_Pop(stack);
	}
	else
	{
		printf("Invalid expression!");
	}

	LinkStack_Destroy(stack);

	return ret;
}