Performing intersection of vector c++

I have 200 vectors of size ranging from 1 to 4000000 stored in vecOfVec. I need to intersect these vectors with a single vector "vecSearched" of size 9000+ elements. I tried to do the same using the following code, however using perf tool I found that the intersection which I am doing is the bottleneck in my code. Is there some way by which I may perform an efficient intersection

#include <cstdlib>
#include <iostream>
#include <vector>

using namespace std;

int main(int argc, char** argv) {
  vector<vector<unsigned> > vecOfVec; //contains 120 vectors of size ranging from 1 to 2000000 elements. All vectors in vecOfVec are sorted
  vector<unsigned> vecSearched; //vector searched in contains 9000+ elements. Vectors in vecSearched are sorted
  for(unsigned kbt=0; kbt<vecOfVec.size(); kbt++)
  {                                  
     //first find first 9 values spaced at equi-distant places, use these 9 values for performing comparisons
     vector<unsigned> equiSpacedVec;                             

     if(((vecSearched[0]))>vecOfVec[kbt][(vecOfVec[kbt].size())-1]) //if beginning of searched vector > last value present in individual vectors of vecOfVec then continue
     {
         continue;                             
     }                         

     unsigned elementIndex=0; //used for iterating over equiSpacedVec                             
     unsigned i=0; //used for iterating over individual buckets vecOfVec[kbt].second
     //search for value in bucket and store it in bucketValPos
     bool firstRun=true;             
     for(vector<unsigned>::iterator itValPos=vecSearched.begin();itValPos!=vecSearched.end();++itValPos)
     {
         //construct a summarized vector out of individual vectors of vecOfVec
         if(firstRun)
         {
             firstRun=false;
             unsigned elementIndex1=0; //used for iterating over equiSpacedVec
             while(elementIndex1<(vecOfVec[kbt].size())) //create a small vector for skipping over the remaining vectors
             {
                  if((elementIndex1+(10000))<(vecOfVec[kbt].size()))
                     elementIndex1+=10000;
                  else
                     break;
                 equiSpacedVec.push_back(vecOfVec[kbt][elementIndex1]);
             }          
         }
         //skip individual vectors of vecOfVec using summarized vector constructed above
         while((!(equiSpacedVec.empty()))&&(equiSpacedVec.size()>(elementIndex+1))&&((*itValPos)>equiSpacedVec[elementIndex+1])){
             elementIndex+=1;
             if((i+100)<(vecOfVec[kbt].size()))
                 i+=100;
         }            
         unsigned j=i;
         while(((*itValPos)>vecOfVec[kbt][j])&&(j<vecOfVec[kbt].size())){
             j++;
         }
         if(j>(vecOfVec[kbt].size()-1)) //element not found even at last position.
         {
             break;
         }              

         if((*itValPos)==vecOfVec[kbt][j])
         {                                     
             //store intersection result
         }
     }
  }
    return 0;
}