I have two vectors holding data objects. Each data object is holding coordinates and some other data. The vectors will always be sorted (first for the x coordinates and then for the y coordinates). I'm trying to delete all objects from both vectors that have coordinates that can not be found in both of the vectors. Here's an MWE of what I'm currently doing:
#include <iostream>
#include <vector>
#include <algorithm>
struct foo{
foo()=default;
foo(int x, int y, double data):x(x),y(y),data(data){}
int x;
int y;
double data;
};
int main()
{
std::vector<foo> vec1=std::vector<foo>(7);
std::vector<foo> vec2=std::vector<foo>(4);
vec1={foo(1,1,0.),foo(1,2,0.),foo(2,1,0.),foo(2,2,0.),foo(2,3,0.),foo(3,1,0.),foo(3,2,0.)};
vec2={foo(1,2,0.),foo(1,3,0.),foo(2,1,0.),foo(3,1,0.)};
for(auto it1=vec1.begin(); it1!=vec1.end();){
auto cur_element=*it1;
auto intersec = std::find_if(vec2.begin(),vec2.end(),[cur_element]
(foo & comp_element)->bool{
return((cur_element.x==comp_element.x) && (cur_element.y==comp_element.y));
});
if(intersec==vec2.end()) it1=vec1.erase(it1);
else ++it1;
}
for(auto it2=vec2.begin(); it2!=vec2.end();){
auto cur_element=*it2;
auto intersec = std::find_if(vec1.begin(),vec1.end(),[cur_element]
(foo & comp_element)->bool{
return((cur_element.x==comp_element.x) && (cur_element.y==comp_element.y));
});
if(intersec==vec1.end()) it2=vec2.erase(it2);
else ++it2;
}
std::cout<<"vec1:\n";
for(auto i: vec1) std::cout<<i.x<<" "<<i.y<<"\n";
std::cout<<"\nvec2:\n";
for(auto i: vec2) std::cout<<i.x<<" "<<i.y<<"\n";
return 0;
}
It works and gives me the expected output.
Anyway it seems really unefficient having to loop through both of the vectors. Is there a more efficient way to achieve the same output?
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