I am new to C and trying to write a program using Xcode that takes the temperature in Fahrenheit and converts it to Celsius, and vise versa. My code so far is below.
#include <stdio.h>
#include "hw2.h"
void convert_temp(int degree1, char scale1, int* degree2, char* scale2){
if (scale1 == 'F') {
*degree2 = ((degree1 - 32) * 5) / 9;
*scale2 = 'C';
}
else {
*degree2 = ((degree1 * 9) / 5) + 32;
*scale2 = 'F';
}
}
int main() {
int degree1, degree2;
char scale1, scale2;
printf("Enter a temperature and a scale\n");
scanf("%d %c", °ree1, &scale1);
convert_temp(degree1, scale1, °ree2, &scale2);
printf("%d %c = %d %c\n", degree1, scale1, degree2, scale2);
return 0;
}
Here is an example of correct i/o:
Enter a temperature and a scale
32 F
32 F = 0 C
However, when I run the code, this is what I get:
Enter a temperature and a scale
32 F
hw2 was compiled with optimization - stepping may behave oddly; variables may not be available.
(lldb)
I cannot understand the output I am getting. Can anybody tell me why I do not get 32 F = 0 C on my output? Everything in my code seems fine to me.
Assuming hw2 is the name of your program, then the debugger is complaining that it was compiled with optimisations turned on, which isn't normal during development, as the optimizer does all sorts of clever things to get the program running faster.
You need to do the following in Xcode:
Ensure you are debugging using the Debug build configuration (Check your Schemes).
Ensure you haven't turned on Optimizations for the Debug build configuration (Check your Build Settings).
Related
So I have just recently started coding and I'm following a book for beginners on C language. One of the programms we learn to write is as follows below. After I compile and run with Dev-C++ it works, but on the console screen appears nothing.
I tried to run the exact same code through Code::Blocks and it works perfectly. Is there any particularity in Dev-C++ I don't know about?
I'll be adding the image of the console of both IDE's consoles.left Code::Blocks, right Dev-C++
Note: the book I'm using was wrote using Code::Blocks.
Note: all other programms I've wrote to this point in Dev-C++ work just fine. This one is the exception.
#include <stdio.h>
main()
{
// Set up the variables, as weel as define a few
char firstInitial, middleInitial;
int number_of_pencils;
int number_of_notebooks;
float pencils = 0.23;
float notebooks = 2.83;
float lunchbox = 4.99;
//The information for the first child
firstInitial = 'J';
middleInitial = 'R';
number_of_pencils = 7;
number_of_notebooks = 4;
printf("%c%c needs %d pencils, %d notebooks, and 1 lunchbox\n",
firstInitial, middleInitial, number_of_pencils,
number_of_notebooks);
printf("The total cost is $%.2f\n\n", number_of_pencils*pencils
+ number_of_notebooks*notebooks + lunchbox);
//The information for the second child
firstInitial = 'A';
middleInitial = 'T';
number_of_pencils = 9;
number_of_notebooks = 2;
printf("%c%c needs %d pencil, %d notebooks, and 1 lunchbox\n",
firstInitial, middleInitial, number_of_pencils,
number_of_notebooks);
printf("The total cost is $%.2f\n",
number_of_pencils*pencils + number_of_notebooks*notebooks +
lunchbox);
return 0;
}
Since I don't know much about coding yet I haven't really tried a diverse ammount of functions, because I simply don't know and understand them yet.
The code works, so I'm happy about it. But I'm still wondering why it didn't for Dev-C++, which is the IDE I was planning to keep on using.
I am trying to do the problem 200B on codeforces. I tested my code, and the output was all right. But when I uploaded it to the online judge system, I failed on the very first test case. It said my output was -0.000000000000, instead of 66.666666666667.
But I have compiled and run on Visual Studio C++ 2010, MacOS clang 13.0.0, and Linux GCC 6.3.0, the outputs were all the same as mine, 66.666666666667. I am very curious and want to figure out in what situation the output could be -0.000000000000.
On my computer,
Input:
3
50 50 100
Output:
66.666666666667
On the online judge system,
Input:
3
50 50 100
Participant's output
-0.000000000000
Jury's answer
66.666666666667
Checker comment
wrong answer 1st numbers differ - expected: '66.66667', found: '-0.00000', error = '1.00000'
#include <stdio.h>
int main(void)
{
int n;
double sumOrange = 0;
double sumDrink = 0;
scanf ("%d", &n);
while (n-- > 0) {
int m;
scanf("%d", &m);
sumOrange += m / 100.0;
sumDrink++;
}
printf("%.12lf\n", (sumOrange / sumDrink) * 100.0);
return 0;
}
I just don't understand why my output could be -0.000000000000. Please help, thanks.
Update: Tested on different versions of GCC (4.9, 5.1, 6.3), the wrong output does not appear. Guess the cause might lie in the specific implementation of printf.
The problem is because printf function in GNU gcc C11 does not support %.12lf format. It should be changed to %.12f For more information, you can read the article below:
Correct format specifier for double in printf
screenshot
I'm fairly new to all of this, so if it is possible could help be really dumbed down for me thank you :).
So I've had about 1 semester of coding at Uni, and we were learning C. Wanting to practice during my holiday I've done some research and opted to download Atom, installed the Gpp-compiler packages, MinGw and created a path, installed git bash etc. according to all the online instructions I could find.
However when I finally thought I was done with all the set up, a problem occured. As I was testing things out, I realised I couldn't run things properly like I was doing on the uni terminal and gedit.
Shown in my screenshot, shouldn't "hello world" be printed first after I try to run it, then I could enter a value and it should print the value or something.
However after running it would come up blank, until I enter something random and then it would print all at once.
Not sure what's happening here or what I did wrong, any guidance would be great thank you.
Edit: this only seems to be a problem, when I use scanf. Without it, everything prints out in order.
My code:
#include <stdio.h>
int main (void) {
int value;
printf("hello world\n");
scanf("%d", &value);
printf("%d", value);
return 0;
}
when I try to call, it comes out blank until I input 45, then it prints out "hello world" "45"
FNATIC P1#PC MINGW64 ~/OneDrive/Documents/CPP
$ gcc -o main main.c
FNATIC P1#PC MINGW64 ~/OneDrive/Documents/CPP
$ ./main
45
hello world
45
Another example:
#include <stdio.h>
#include <math.h>
int main(void) {
double sideA, sideB, sideC;
double s, area;
printf("Please enter 3 sides of your triangle: \n");
scanf("%lf %lf %lf", &sideA, &sideB, &sideC);
s = (sideA + sideB + sideC) / 2;
area = sqrt(s * (s - sideA) * (s - sideB) * (s - sideC));
printf("%lf\n", area);
return 0;
}
Output: nothing came out until I entered (2 3 4) and (5.31 4.2 7.77)
FNATIC P1#PC MINGW64 ~/OneDrive/Documents/CPP
$ ./heron
2 3 4
Please enter 3 sides of your triangle:
2.904738
FNATIC P1#PC MINGW64 ~/OneDrive/Documents/CPP
$ ./heron
5.31 4.2 7.77
Please enter 3 sides of your triangle:
10.542172
Here is my code that I am having issues with. The goal of the program is to scan in a bunch of doubles and perform some simple statistical operations on them. The line I am having the issue with is the fgets(). I have included the stdio.h, it's just not showing up in the code. My actual question is where are the stdin and NULL giving me issues when I though they were part of the language? The exact error I am getting is that both Symbol stdin and NULL could not be resolved.
/*
* simpleStats.c
*
* Created on: Sep 17, 2018
* Author: David Liotta
*/
#include <stdio.h>
#define BUFSIZE 256
int main(){
double n, max, min, sum, mean;
char line[BUFSIZE];
int numsRead = 0;
int numOfItems = 1;
n = -1;
max = n;
min = n;
sum = n;
while(n != 0 && fgets(line, BUFSIZE, stdin ) != NULL){
numsRead = sscanf(line, "%f", &n);
if(numsRead == 1 && n != 0){
numOfItems++;
if(n > max)
max = n;
if(n < min)
min = n;
sum = sum + n;
}
if(numsRead == 0)
printf("Bad input\n");
}
mean = sum / numOfItems;
printf("# of items: %i", numOfItems);
printf("\nSum: %f.3", sum);
printf("\nMax: %f.3", max);
printf("\nMin: %f.3", min);
printf("\nMean: %f.3", mean);
}
This code should compile. I suspect something might be wrong with your development environment.
Since you're running Eclipse, I'm assuming that your compiler is GCC. I may be wrong though.
Try to locate your compiler executable, and run the compilation by hand:
gcc -Wall -o simpleStats simpleStats.c
or, if you're on Windows:
gcc.exe -Wall -o simpleStats.exe simpleStats.c
You may have to specify the full path to gcc.exe, (depending on your environment, it might even be called something else; you may be able to retrieve the full path from the console window in Eclipse).
Pay close attention to the output. Copy/paste the full output verbatim in your original post if you can (do not rephrase the warnings / error messages).
I seldom use Eclipse, but with most IDEs you get to chose what kind of project you want to create. Make sure you selected something like "console application", the error you're referring to (stdin not being resolved) may suggest a linker error. Again, it's hard to tell without the exact GCC output.
A couple more things to check:
make sure your compiler and its dependencies are properly installed,
make sure that this compiler is targeted at Windows (or whatever OS you use), not at some exotic embedded platform,
most development environments come with a bunch of sample projects, see if you can build one.
The problem I was having ended up being the compiler not correctly reading the code. I used a different compiler, and with some minor syntax changes, the code worked fine.
My Thermo professor assigned our class a computational project in which we have to calculate some thermodynamic functions. He provided us with some code to work off of which is a program that essentially finds the area under a curve between two points for the function x^2. The code is said to be correct and it looks correct to me. However, I've been having FREQUENT problems with all of my programs giving me the error "'File location'.exe is not recognized as internal or external command, operable programs or batch files." upon initial running of a project or [mostly] reopening projects.
I've been researching the problem for many hours. I tried adjusting the environmental variables like so many other sites suggested, but I'm either not doing it right or it's not working. All I keep reading about is people explaining the purpose of an .exe file and that I have to locate that file and open that. The problem is that I cannot find ANY .exe file. There is the project I created with the source.c file I created and wrote the program in. Everything else has lengthy extensions that I've never seen before.
I'm growing increasingly impatient with Visual Studios' inconsistent behavior lately. I've just made the switch from MATLAB, which although is an inferior programming language, is far more user friendly and easier to program with. For those of you interested in the code I'm running, it is below:
#include <stdio.h>
#include <iostream>
#include <math.h>
using namespace std;
double integration();
double integration()
{
int num_of_intervals = 4, i;
double final_sum = 0, lower_limit = 2, upper_limit = 3, var, y = 1, x;
x = (upper_limit - lower_limit) / num_of_intervals; // Calculating delta x value
if(num_of_intervals % 2 != 0) //Simpson's rule can be performed only on even number of intervals
{
printf("Cannot perform integration. Number of intervals should be even");
return 0;
}
for(i = 0 ; i < num_of_intervals ; i++)
{
if(i != 0) //Coefficients for even and odd places. Even places, it is 2 and for odd it is 4.
{
if(i % 2 == 0)
y = 2;
else
y = 4;
}
var = lower_limit + (i * x);// Calculating the function variable value
final_sum = final_sum + (pow(var, 2) * y); //Calculating the sum
}
final_sum = (final_sum + pow(upper_limit , 2)) * x / 3; //Final sum
return final_sum;
}
int main()
{
printf("The integral value of x2 between limits 2 and 3 is %lf \n" , integration());
system("PAUSE");
return 0;
}
Thanks in advance,
Dom