Hi,
I'm in the process of building a RPN calculator, but I am confused about how to store data from the user. If you take a look at the attachment picture, you will understand what I mean:
The Hints: section wants me to use the following code to read operators and operands:
If I'm entering long data, how is that possible?Code:scanf("%c", &ch);
I would appreciate any help.Code:Enter an RPN expression: 1 2 3 * + =
You're not entering long data in your example. 1, 2, 3, *, + are all single characters and can be read quite easily using %c. If you wanted to allow two-digit numbers, then things might get a little interesting; but even then, you'd probably want to read one character at a time.
The hint says to use scanf(" %c", &ch);. Note the space.
It is too clear and so it is hard to see.
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Had he known what fire was,
He could have cooked his rice much sooner.
Aha, I missed that space! I will try to work it out, thanks.Originally Posted by King Mir
You need to insert each char (it'll be ASCII - convert to a number) into an array (the array is used as the stack) and process this array of numbers whenever you receive an operator (*, / etc) instead of a number.
Seems the examples in the attached assume single-digit numbers with no use of an "enter" key (or its equivalent). Not sure if that's part of your requirements?
Ever use an HP calculator?
Okay, I've gotten this far:
Notice that I use a 0 char to terminate the loop, but there is a flaw in doing that: what if I have a 0 in the middle of my data? I tried a null, but that doesn't seem to work.Code://** Include Files ****************************************************** #include <stdio.h> #include <stdlib.h> //** Defines ************************************************************ #define STACK_SIZE 100 //** External Variables ************************************************* int contents[STACK_SIZE]; int main() { int i, j; char ch; printf("Enter integer: "); i = 0; do { scanf(" %c", &contents[i]); printf("You entered %c \r\n", contents[i]); }while(contents[i++] != '0'); for(j = i; j >= 0; j--) { printf("contents[%d] = %c \r\n", j, contents[j]); } printf("\n"); system("PAUSE"); }
Last edited by ElectroNerd; 06-06-2011 at 02:43 PM.
The example in the picture is using a q not a 0 to terminate the loop.
Quzah.
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