RPN notation in C
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Hello, I am trying to code a program which evaluates expressions in reverse polish notations. For now, it should work only with numbers and operands ( +, -, * and / ). Here is the code I have written:
#include #include #include #include #include #define MAX 41
int t, i, v1, v2;
int top = -1;
char seq[40];
char rpn[40];
char fin[40];
int main()
{
printf("introduce the numbers and opreands in rpn \n");
fgets(seq,40,stdin);t=strlen(seq);
for (i=0;i<=t;i++)
if (isdigit(seq[i]))
{
Push(rpn, seq[i]);
}
if (ispunct(seq[i]));v1=pop(rpn); v2=pop(rpn); if (seq\[i\] = '+'); push(fin, v1+v2); if (seq\[i\] = '-'); push(fin, v1-v2); if (seq\[i\] = '\*'); push(fin, v1\*v2); if (seq\[i\] = '/'); push(fin, v1/v2);printf(fin);
}int isempty() {
if(top == -1)
return 1;
else
return 0;
}int isfull() {
if(top == MAX)
return 1;
else
return 0;
}int peek() {
return seq[top];
}int pop() {
int data;if(!isempty()) {
data = seq[top];
top = top - 1;
return data;
}else {
printf("Could not retrieve data, Stack is empty.\n");
}
}int push(int data) {
if(!isfull()) {
top = top + 1;
seq[top] = data;
}else {
printf("Could not insert data, Stack is full.\n");
}
}There are, I think, some big mistakes i can't solve by myself, since im a beginner in programming. I have searched for a solution on the internet, but i don't truly understand them. The idea of my code is that the user types some numbers and operands like this: 2 3 +. In this case, the program should add 2 and 3 in a stack and when it reads and operator, pop the lasts 2 numbers on the pile and do the corresponding opperation. When i build it I have this errors:
||=== Build file: "no target" in "no project" (compiler: unknown) ===|
C:\Users\Jordi\Documents\RPN.o:RPN.c|| undefined reference to `Push|
||error: ld returned 1 exit status|
||=== Build failed: 2 error(s), 0 warning(s) (0 minute(s), 0 second(s)) ===| -
Hello, I am trying to code a program which evaluates expressions in reverse polish notations. For now, it should work only with numbers and operands ( +, -, * and / ). Here is the code I have written:
#include #include #include #include #include #define MAX 41
int t, i, v1, v2;
int top = -1;
char seq[40];
char rpn[40];
char fin[40];
int main()
{
printf("introduce the numbers and opreands in rpn \n");
fgets(seq,40,stdin);t=strlen(seq);
for (i=0;i<=t;i++)
if (isdigit(seq[i]))
{
Push(rpn, seq[i]);
}
if (ispunct(seq[i]));v1=pop(rpn); v2=pop(rpn); if (seq\[i\] = '+'); push(fin, v1+v2); if (seq\[i\] = '-'); push(fin, v1-v2); if (seq\[i\] = '\*'); push(fin, v1\*v2); if (seq\[i\] = '/'); push(fin, v1/v2);printf(fin);
}int isempty() {
if(top == -1)
return 1;
else
return 0;
}int isfull() {
if(top == MAX)
return 1;
else
return 0;
}int peek() {
return seq[top];
}int pop() {
int data;if(!isempty()) {
data = seq[top];
top = top - 1;
return data;
}else {
printf("Could not retrieve data, Stack is empty.\n");
}
}int push(int data) {
if(!isfull()) {
top = top + 1;
seq[top] = data;
}else {
printf("Could not insert data, Stack is full.\n");
}
}There are, I think, some big mistakes i can't solve by myself, since im a beginner in programming. I have searched for a solution on the internet, but i don't truly understand them. The idea of my code is that the user types some numbers and operands like this: 2 3 +. In this case, the program should add 2 and 3 in a stack and when it reads and operator, pop the lasts 2 numbers on the pile and do the corresponding opperation. When i build it I have this errors:
||=== Build file: "no target" in "no project" (compiler: unknown) ===|
C:\Users\Jordi\Documents\RPN.o:RPN.c|| undefined reference to `Push|
||error: ld returned 1 exit status|
||=== Build failed: 2 error(s), 0 warning(s) (0 minute(s), 0 second(s)) ===| -
Unless this is a fragment, it seems like you have done no effort to actually implement push and pop. `strlen` (the usual one) is from string.h which you should therefore include.
You are right, sorry, I even forgot to put them in the code! This is something a partner gave and explained to me. There are some functions i dont even use. It's because I understand it i didn't put in here. My bad. The full code looks like:
#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <string.h>
#include <conio.h>
#define MAX 41int t, i, v1, v2;
int top = -1;
char seq[40];
char rpn[40];
char fin[40];
int main()
{
printf("introduce the numbers and opreands in rpn \n");
fgets(seq,40,stdin);t=strlen(seq);
for (i=0;i<=t;i++)
if (isdigit(seq[i]))
{
Push(rpn, seq[i]);
}
if (ispunct(seq[i]));v1=pop(rpn); v2=pop(rpn); if (seq\[i\] = '+'); push(fin, v1+v2); if (seq\[i\] = '-'); push(fin, v1-v2); if (seq\[i\] = '\*'); push(fin, v1\*v2); if (seq\[i\] = '/'); push(fin, v1/v2);printf(fin);
}int isempty() {
if(top == -1)
return 1;
else
return 0;
}int isfull() {
if(top == MAX)
return 1;
else
return 0;
}int peek() {
return seq[top];
}int pop() {
int data;if(!isempty()) {
data = seq[top];
top = top - 1;
return data;
}else {
printf("Could not retrieve data, Stack is empty.\n");
}
}int push(int data) {
if(!isfull()) {
top = top + 1;
seq[top] = data;
}else {
printf("Could not insert data, Stack is full.\n");
}
} -
You are right, sorry, I even forgot to put them in the code! This is something a partner gave and explained to me. There are some functions i dont even use. It's because I understand it i didn't put in here. My bad. The full code looks like:
#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <string.h>
#include <conio.h>
#define MAX 41int t, i, v1, v2;
int top = -1;
char seq[40];
char rpn[40];
char fin[40];
int main()
{
printf("introduce the numbers and opreands in rpn \n");
fgets(seq,40,stdin);t=strlen(seq);
for (i=0;i<=t;i++)
if (isdigit(seq[i]))
{
Push(rpn, seq[i]);
}
if (ispunct(seq[i]));v1=pop(rpn); v2=pop(rpn); if (seq\[i\] = '+'); push(fin, v1+v2); if (seq\[i\] = '-'); push(fin, v1-v2); if (seq\[i\] = '\*'); push(fin, v1\*v2); if (seq\[i\] = '/'); push(fin, v1/v2);printf(fin);
}int isempty() {
if(top == -1)
return 1;
else
return 0;
}int isfull() {
if(top == MAX)
return 1;
else
return 0;
}int peek() {
return seq[top];
}int pop() {
int data;if(!isempty()) {
data = seq[top];
top = top - 1;
return data;
}else {
printf("Could not retrieve data, Stack is empty.\n");
}
}int push(int data) {
if(!isfull()) {
top = top + 1;
seq[top] = data;
}else {
printf("Could not insert data, Stack is full.\n");
}
} -
You are right, sorry, I even forgot to put them in the code! This is something a partner gave and explained to me. There are some functions i dont even use. It's because I understand it i didn't put in here. My bad. The full code looks like:
#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <string.h>
#include <conio.h>
#define MAX 41int t, i, v1, v2;
int top = -1;
char seq[40];
char rpn[40];
char fin[40];
int main()
{
printf("introduce the numbers and opreands in rpn \n");
fgets(seq,40,stdin);t=strlen(seq);
for (i=0;i<=t;i++)
if (isdigit(seq[i]))
{
Push(rpn, seq[i]);
}
if (ispunct(seq[i]));v1=pop(rpn); v2=pop(rpn); if (seq\[i\] = '+'); push(fin, v1+v2); if (seq\[i\] = '-'); push(fin, v1-v2); if (seq\[i\] = '\*'); push(fin, v1\*v2); if (seq\[i\] = '/'); push(fin, v1/v2);printf(fin);
}int isempty() {
if(top == -1)
return 1;
else
return 0;
}int isfull() {
if(top == MAX)
return 1;
else
return 0;
}int peek() {
return seq[top];
}int pop() {
int data;if(!isempty()) {
data = seq[top];
top = top - 1;
return data;
}else {
printf("Could not retrieve data, Stack is empty.\n");
}
}int push(int data) {
if(!isfull()) {
top = top + 1;
seq[top] = data;
}else {
printf("Could not insert data, Stack is full.\n");
}
}Keep in mind that the c/c++ is case sensitive. I'm looking at this line in particular.
Push(rpn, seq[i]);
"the debugger doesn't tell me anything because this code compiles just fine" - random QA comment "Facebook is where you tell lies to your friends. Twitter is where you tell the truth to strangers." - chriselst "I don't drink any more... then again, I don't drink any less." - Mike Mullikins uncle
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You are right, sorry, I even forgot to put them in the code! This is something a partner gave and explained to me. There are some functions i dont even use. It's because I understand it i didn't put in here. My bad. The full code looks like:
#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <string.h>
#include <conio.h>
#define MAX 41int t, i, v1, v2;
int top = -1;
char seq[40];
char rpn[40];
char fin[40];
int main()
{
printf("introduce the numbers and opreands in rpn \n");
fgets(seq,40,stdin);t=strlen(seq);
for (i=0;i<=t;i++)
if (isdigit(seq[i]))
{
Push(rpn, seq[i]);
}
if (ispunct(seq[i]));v1=pop(rpn); v2=pop(rpn); if (seq\[i\] = '+'); push(fin, v1+v2); if (seq\[i\] = '-'); push(fin, v1-v2); if (seq\[i\] = '\*'); push(fin, v1\*v2); if (seq\[i\] = '/'); push(fin, v1/v2);printf(fin);
}int isempty() {
if(top == -1)
return 1;
else
return 0;
}int isfull() {
if(top == MAX)
return 1;
else
return 0;
}int peek() {
return seq[top];
}int pop() {
int data;if(!isempty()) {
data = seq[top];
top = top - 1;
return data;
}else {
printf("Could not retrieve data, Stack is empty.\n");
}
}int push(int data) {
if(!isfull()) {
top = top + 1;
seq[top] = data;
}else {
printf("Could not insert data, Stack is full.\n");
}
}Member 12529159 wrote:
This is something a partner gave...
Ahh, the classic "copy & paste" bug. I'm usually the one to get chided for printing off code snippets and retype them line by line into my project. Consequently, I've never been a victim of this type of problem.
"One man's wage rise is another man's price increase." - Harold Wilson
"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons
"You can easily judge the character of a man by how he treats those who can do nothing for him." - James D. Miles
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Hello, I am trying to code a program which evaluates expressions in reverse polish notations. For now, it should work only with numbers and operands ( +, -, * and / ). Here is the code I have written:
#include #include #include #include #include #define MAX 41
int t, i, v1, v2;
int top = -1;
char seq[40];
char rpn[40];
char fin[40];
int main()
{
printf("introduce the numbers and opreands in rpn \n");
fgets(seq,40,stdin);t=strlen(seq);
for (i=0;i<=t;i++)
if (isdigit(seq[i]))
{
Push(rpn, seq[i]);
}
if (ispunct(seq[i]));v1=pop(rpn); v2=pop(rpn); if (seq\[i\] = '+'); push(fin, v1+v2); if (seq\[i\] = '-'); push(fin, v1-v2); if (seq\[i\] = '\*'); push(fin, v1\*v2); if (seq\[i\] = '/'); push(fin, v1/v2);printf(fin);
}int isempty() {
if(top == -1)
return 1;
else
return 0;
}int isfull() {
if(top == MAX)
return 1;
else
return 0;
}int peek() {
return seq[top];
}int pop() {
int data;if(!isempty()) {
data = seq[top];
top = top - 1;
return data;
}else {
printf("Could not retrieve data, Stack is empty.\n");
}
}int push(int data) {
if(!isfull()) {
top = top + 1;
seq[top] = data;
}else {
printf("Could not insert data, Stack is full.\n");
}
}There are, I think, some big mistakes i can't solve by myself, since im a beginner in programming. I have searched for a solution on the internet, but i don't truly understand them. The idea of my code is that the user types some numbers and operands like this: 2 3 +. In this case, the program should add 2 and 3 in a stack and when it reads and operator, pop the lasts 2 numbers on the pile and do the corresponding opperation. When i build it I have this errors:
||=== Build file: "no target" in "no project" (compiler: unknown) ===|
C:\Users\Jordi\Documents\RPN.o:RPN.c|| undefined reference to `Push|
||error: ld returned 1 exit status|
||=== Build failed: 2 error(s), 0 warning(s) (0 minute(s), 0 second(s)) ===|Member 12529159 wrote:
There are, I think, some big mistakes
Yes, this will not compile, and even if it did, none of this code is going to work. You are reading a string into the array
seqand then using Push to copy characters back into the same array. You are also storing everything as characters but when you use Pop, you think you are rectrieving an integer. And you assume that each string will be two digits followed by a mathematical symbol.