Checking whether an element exist or not in the map within map

Question

I have a map of the form map > :

For Example: I am storing the intensity value at 2-D co-ordinate(x,y) i

Answer 1

This is bit ugly but should work too : (using C++11)

std::map > intensityValue;
int x,y;
auto it = std::find_if(intensityValue.begin(),
                    intensityValue.end(),
                    [x,y](const std::pair>& p){
                      return p.first==x && 
                             p.second.find(y) !=p.second.end();
                    }
                    );

  if(it != intensityValue.end())
  {
      //Got it !
  }