Bucket Sort with a custom data structure - c++

Question

My program is tasked with sorting points on an x-y plane, given by the user, according to their distance from the origin using bucket sort. In the instance of having two points with the same distance, the point with the smallest x-coordinate would be selected as the first point. If both the distance and the x-coordinate are the same, the element with the smallest y-coordinate will come first. The output is the points themselves, not their distances. The most logical way I've found to do it so far is to create a custom data structure that houses both the x coordinate, y-coordinate, and its distance in one element. The problem I have at the moment is my current algorithm for standard vectors of doubles, and I have no idea how to convert the sort to fit my needs. Any ideas or suggestions would be helpful.
Here is the layout of the structure:
struct point {
double xc;
double yc;
double dist; };
The current bucket sort, which works fine with vectors of doubles.
void bucketSort(vector<double> &arr) {
int n = B.size();
vector<point> b[n];
for (int i=0; i<n; i++)
{
int bi = n*arr[i];
b[bi].push_back(arr[i]);
}
for (int i=0; i<n; i++)
sort(b[i].begin(), b[i].end());
int index = 0;
for (int i = 0; i < n; i++){
for (int j = 0; j < b[i].size(); j++){
arr[index++] = b[i][j]; }
}
}
The entirety of the code, as of now.
using namespace std;
struct point {
double xc;
double yc;
double dist;
};
vector<double> A;
vector<double> B;
double findDistance(double x = 0, double y = 0) {
double x2 = pow(x, 2);
double y2 = pow(y, 2);
double z = x2 + y2;
double final = sqrt(z);
return final;
}
void bucketSort(vector<double> &arr)
{
int n = B.size();
vector<point> b[n];
for (int i=0; i<n; i++)
{
int bi = n*arr[i];
b[bi].push_back(arr[i]);
}
for (int i=0; i<n; i++)
sort(b[i].begin(), b[i].end());
int index = 0;
for (int i = 0; i < n; i++){
for (int j = 0; j < b[i].size(); j++){
arr[index++] = b[i][j]; }
}
}
int main(){
double number; int t = 0;
while (cin >> number){
A.push_back(number); }
struct point C[A.size()];
while (t < A.size()){
C[t / 2].xc = A[t]; C[t / 2].yc = A[t + 1];
C[t / 2].dist = (findDistance(A[t], A[t + 1])); t += 2; }
cout << setprecision(6); cout << fixed; ;
bucketSort(C);
cout << showpos; cout << fixed;
int x = 0;
while (x < (A.size() / 2)){
cout << C[x].xc << " " << C[x].yc << endl;
x++;
}
}
A vector of doubles B is here because initially, I was trying to get it done with multiple vectors of doubles.
Here is a sample of the input:
0.2 0.38
0.6516 -0.1
-0.3 0.41
-0.38 0.2
Sample output:
-0.380000 +0.200000
+0.200000 +0.380000
-0.300000 +0.410000
+0.651600 -0.100000
I realize that point could have a lot more functions added to it to make it more usable in general, but I'm aiming for just enough to get the current job. Any suggestions or help would be greatly appreciated. Please and thank you.

Answer 1

I would suggest one of there 2 options -
make point a class, not an struct, and overload the < operator, thus making the sort work well.
2.use the sort by function instead of the normal sort:
Firstly, add a compare function:
bool comparePoint(point* a, point* b) {
return true if a < b;
}
the function above would compare the 2 points, according to any rules you like, depends on your code.
and instead of the sort use:
std::sort(b[i].begin(), b[i].end(),comparePoint);
that should work for you.