Given two arrays a and b .Find all pairs of elements (a1,b1) such that a1 belongs to Array A and b1 belongs to Array B whose sum a1+b1 = k

Question

I am looking for the solution of following algorithm with minimal time and space complexity.

Given two arrays a and b, find all pairs of elements (a1,

Answer 1

I used C++ and it seemed to give me the desired result. Hope this is what you were looking for.

using namespace std;

using data=std::pair;

void search_pairs(std::vector& A, std::vector& B, const int total, std::vector& output){

  std::sort(A.begin(),A.end(),[](const int i,const int j)->bool{return (ibool{return (a* minV(nullptr);
  std::vector* maxV(nullptr);
  if(A.size()>B.size()) {minV=&B;maxV=&A;}
  else {minV=&A;maxV=&B;}
  for(auto&& itr:(*minV) ){
    auto remain(total-itr);
    if (std::binary_search (maxV->begin(), maxV->end(), remain)){
      data d{itr,remain};
      if (minV==&B) std::swap(d.first,d.second);
      output.push_back(d);
    }
  }
  if (minV==&B) std::reverse(output.begin(),output.end());  
}

int main() {

    size_t nb(0);
    scanf("%lu",&nb);
    for (size_t i=0;i A,B;
        for (size_t i=0;i output;
        search_pairs(A, B, total, output);
    auto itr=std::begin(output);
    if (itr==std::end(output)) printf("-1"); 
    while (itr!=std::end(output)){
      printf("%d %d",(*itr).first, (*itr).second);
      if (++itr!=std::end(output)) printf(", ");
    }
        printf("\n");
    }
    //code
    return 0;
}