二维vector的遍历

turnPoints是一个二维vector容器，下面代码实现了二维vector的逐个遍历，类似于以为数组

float distance = 100;
for(int i = 0; i < points.size()-1; i++)
for(int j = i+1; j<points.size(); j++)
{
if(distance < (points[i]-points[j]).distance()))
distance = (points[i]-points[j]).distance());
}

vector<vector<Point>>turnPoints;

for(int i = 0; i < turnPoints.size()-1; i++)
        for(int j = 0; j < turnPoints[i].size()-1; j++)
            for(int m = i; m < turnPoints.size(); m++)
            {
                int n;
                if( m == i)
                    n = j+1;
                else n = 0;

                for( ; n < turnPoints[m].size(); n++)
                {
                    FPoint3 p = turnPoints[i][j] - turnPoints[m][n];
                    if(p.Length() < distance)
                        distance = p.Length();
                    if(p.Length() < 10)
                    {                
                        FPoint3 midP = (turnPoints[i][j] + turnPoints[m][n])/2;
                        turnPoints[i][j] = midP;
                        turnPoints[m][n] = midP;
                    }
                        
            
                }
            }