I want to std::sort a vector full of three dimensional points in a way that each point is primarily aligned based on the z value, secondarily by y value, and at last by the x value.
A desired output example could be
192 1 1
200 1 1
208 1 2
-296 2 2
-288 2 3
However, my approach to std::sort seems to be not very nice. On the one hand there is an == on a float. On the other hand my functor is rather complicated. Additionally, this approach sucks if I have a N-dimensional point. Is there a better way?
Example code:
// Example program
#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <stdio.h>
struct point {
float x;
float y;
float z;
};
int main()
{
std::vector<point> foo = {
{ 1 , 72 , 10 },
{ 2 , 72 , 9 },
{ 3 , 72 , 8 },
{ 32 , 71 , 7 },
{ 4 , 70 , -152 },
{ 32 , 72 , -144 },
{ 5 , 72 , -136 },
{ 5 , 72 , -128 },
{ 5 , 72 , -120 },
{ 32 , 72 , -112 },
{ 32 , 72 , -104 },
{ 32 , 72 , -96 },
{ 32 , 72 , -88 },
{ 32 , 3 , -80 }
};
std::sort(
foo.begin(),
foo.end(),
[](const point &a, const point &b) {
if (a.z < b.z) return true;
if (a.z == b.z && a.y < b.y) return true;
if (a.z == b.z && a.y == b.y && a.x < b.x) return true;
return false;
}
);
for(auto p : foo) {
printf("%f,%f,%f\n", p.x, p.y, p.z);
}
}
