Hello, I need help with task, I already did to calculate distance, but IDK how to output the biggest coordination distance with numbers, and then sort all coordinates.
#Coordinates distance and more
lapis jay
stiff sorrelBOT
lapis jay
#include <iostream>
#include <fstream>
#include <cmath>
#include <iomanip>
using namespace std;
int main ()
{
int n;
fstream duom("duom.txt");
fstream rez("rez.txt");
duom >> n;
int x[n], y[n];
double distance[n];
for (int i=1; i<=n; i++){
duom >> x[i];
duom >> y[i];
distance[i]=sqrt(pow(0-x[i],2)+pow(0-y[i],2));
cout << distance[i] << endl;
}
return 0;
}
this what I did, but I need to do how task asks but IDK how to get that the answer
idk how to do this
ripe relic
you don't actually have to sort all of the values bec9ause you only need to sort the highest so far value
so if you would have 3 points (in this order) with distance 1,4,2
then you would first store the distance of 1 (because it's the highest so far) and when the 4 comes you compare it to that. because 4 is greater than 1 you store it. then this becomes the new highest so far value. You would keep the value 4 after comparing it to 2 because it is still the highest so far value.
(You also need to keep track of the points while you are doing this but that can be handled in the same if-statement)
Another approach you could take is to store the values in a point struct and then std::sort it with a lambda that sorts based on distance
lapis jay
But i dont know how to do that
And I don't know how to make the coordinates be written to the answer according to distances
unborn sinew
<@793097924279664650> can you help me?
do you know how structs work
lapis jay
not really
unborn sinew
not really
have you used struct before
lapis jay
Not yet
lapis jay
```
#include <iostream>
#include <fstream>
#include <cmath>
#include <iomanip>
...
only did that on this
unborn sinew
only did that on this
they are asking you to sort the points right?
do you know how to sort arrays?
lapis jay
I know how sort but I dont know how to sort coordinates number by them distance
I already did distance now I just need to do on 1.1 the that the answer is the largest distance and its coordinates, but I don't know how to write the code
unborn sinew
I know how sort but I dont know how to sort coordinates number by them distance
this is why I was asking about struct
because
you can define a point as a struct with 2 integers
so you will have
lapis jay
But I dont know how to use struct 🙄
unborn sinew
But I dont know how to use struct 🙄
okay fine, we will do this the hard way
since your teacher aparently wants to make you miserable
lapis jay
You can do it in any way, because you don't specify which way to do it, but then I will need to learn "struct"
unborn sinew
You can do it in any way, because you don't specify which way to do it, but then...
so you are telling me I can use thing you have not learned yet?
lapis jay
Yes, because he expects us to learn more at home
lapis jay
Okay
unborn sinew
Okay
#include <iostream>
#include <fstream>
#include <algorithm>
struct point
{
int x;
int y;
};
double getDistanceToOrigin(const point& p)
{
return sqrt(p.x*p.x + p.y*p.y);
}
bool compareDistanceToOrigin(const point& left, const point& right)
{
return getDistanceToOrigin(left) < getDistanceToOrigin(right);
}
int main ()
{
std::ifstream inputFile("duom.txt");
//std::ofstream results("result.txt");
const int MAX = 50 * 1000;
point arr[MAX];
int n = 0;
inputFile>>n;
if(n > MAX)
{
std::cout<<"error n is too large\n";
exit(1);
}
for (int i=0; i<n; i++){
inputFile>>arr[i].x;
inputFile>>arr[i].y;
}
std::sort(arr, arr+n, compareDistanceToOrigin);
for (int i=0; i<n; i++){
std::cout<<arr[i].x<<" "<<arr[i].y<<" distance to origin = "<<getDistanceToOrigin(arr[i])<<"\n";
}
return 0;
}
@lapis jay
test it
lapis jay
1.2 working
unborn sinew
1.2 working
so do you understand what I wrote
unborn sinew
but at first not getting 1.1
when the points are sorted, the element arr[n-1] is the point whose distance is the largest
away from origin
lapis jay
so how can I get this answer to file
unborn sinew
but only need 1.1 to file
aha
well then
#include <iostream>
#include <fstream>
#include <algorithm>
struct point
{
int x;
int y;
};
double getDistanceToOrigin(const point& p)
{
return sqrt(p.x*p.x + p.y*p.y);
}
bool compareDistanceToOrigin(const point& left, const point& right)
{
return getDistanceToOrigin(left) < getDistanceToOrigin(right);
}
int main ()
{
std::ifstream inputFile("duom.txt");
std::ofstream results("result.txt");
const int MAX = 50 * 1000;
point arr[MAX];
int n = 0;
inputFile>>n;
if(n > MAX)
{
std::cout<<"error n is too large\n";
exit(1);
}
for (int i=0; i<n; i++){
inputFile>>arr[i].x;
inputFile>>arr[i].y;
}
std::sort(arr, arr+n, compareDistanceToOrigin);
results<<arr[n-1].x<<" "<<arr[n-1].y<<" distance to origin = "<<getDistanceToOrigin(arr[n-1])<<"\n";
for (int i=0; i<n; i++){
std::cout<<arr[i].x<<" "<<arr[i].y<<" distance to origin = "<<getDistanceToOrigin(arr[i])<<"\n";
}
return 0;
}
@lapis jay
unborn sinew
Now I will try to understand everything how working
you know, you can ask me
lapis jay
btw thank you very much
Yea I will ask
What is the std before sort/cout/ifstream/ofstream?
Never used that before
unborn sinew
What is the std before sort/cout/ifstream/ofstream?
that is the namespace std
the standard namespace
all things from the standard C++ library are taken from there
other libraries can have their own namespace
lapis jay
Okay
So the struct is to group several related variables into one place, how I understand
stiff sorrelBOT
@lapis jay Has your question been resolved? If so, run !solved :)
unborn sinew
So the struct is to group several related variables into one place, how I unders...
yes
ripe relic
const point& p```means that you are referencing a variable instead of copying itwdym?