Help Finding Error In std::find code

[Adam Teasdale Hartshorne]

I would be extremely grateful if somebody could tell me what as I
getting wrong with this little bit of code to find the index of a
particular element in a std::vector

std::vector<int> allVertices ;
getTriangleVertices(t[0], allVertices) ; //Fills the allVertices vector
getTriangleVertices(t[1], allVertices) ;

print("All Vertices", allVertices) ;

std::vector<int> tempSpareVertex (getUniqueElements(allVertices)) ;
print("Temp Spare Vertices", tempSpareVertex) ;

std::vector<int>::const_iterator it (std::find(allVertices.begin(),
allVertices.end(), tempSpareVertex[0]));

int index = it - allVertices.begin() ;
printf("Spare Vertex 0 Position:- %i \n", index) ;

and the debug shows things like this

All Vertices: 72 6 50 50 6 46
Temp Spare Vertices: 46 72
Spare Vertex 0 Position:- 2

which is clearly the wrong index.


Adam

 

[Dave Townsend]

I would be extremely grateful if somebody could tell me what as I
getting wrong with this little bit of code to find the index of a
particular element in a std::vector

std::vector<int> allVertices ;
getTriangleVertices(t[0], allVertices) ; //Fills the allVertices vector
getTriangleVertices(t[1], allVertices) ;

print("All Vertices", allVertices) ;

std::vector<int> tempSpareVertex (getUniqueElements(allVertices)) ;
print("Temp Spare Vertices", tempSpareVertex) ;

std::vector<int>::const_iterator it (std::find(allVertices.begin(),
allVertices.end(), tempSpareVertex[0]));

int index = it - allVertices.begin() ;
printf("Spare Vertex 0 Position:- %i \n", index) ;

and the debug shows things like this

All Vertices: 72 6 50 50 6 46
Temp Spare Vertices: 46 72
Spare Vertex 0 Position:- 2

which is clearly the wrong index.


Adam

Please post a working piece of code, clearly the code you posted is not
valid. Here is
a working demonstration that std::find is working correctly for the data you
have given:



int main(int argc, char* argv[])
{
std::vector<int> allVertices ;
std::vector<int> tempSpareVertex;
allVertices.push_back(72);
allVertices.push_back(6);
allVertices.push_back(50);
allVertices.push_back(50);
allVertices.push_back(6);
allVertices.push_back(46);


tempSpareVertex.push_back(46);
tempSpareVertex.push_back(72);

vector<int>::const_iterator it (std::find(allVertices.begin(),
allVertices.end(), tempSpareVertex[0] ));


int index = it - allVertices.begin() ;
printf("Spare Vertex 0 Position:- %i \n", index) ; // prints 5 like we
expected.


return 0;
}