how to define two dimensional vector which element is vector of variable size?

Question

I want to define a vector with 20 rows and 4 columns which its elements is vector with variable size like this

result={ 
   {1,2,3},{5,4},{1},{10,15,16}
   {5},{1,2},{1,2,3},{1,4,5,6}
    ...

}

Result at first is empty ... some part of my code is written below and 'result' update if condition is true

for(int i=0;i<20;i++){

    hash_1=hash_images[i];

    for(int j=i+1;j<20;j++){

        hash_2=hash_images[j];
        dis=hammingDist(hash_1.c_str(),hash_2.c_str());

        for(int t=0;t<4;t++){

            if (dis<=t){
                  ? result[i][t].push_back(somthing);   
            }
        } 
    }
}

std::vector> vec = { {1, 2, 3}, {2, 3}, {2, 7, 9} }; will work — Yashas, Dec 10 '17 at 14:21
I want to append item to vector but this dosnt work...result at end of code should be like that — Z. Tabatabai, Dec 10 '17 at 14:32

score 0 · Answer 1 · answered Dec 11 '17 at 14:44

Define a 3-dimensional vector as follow:

vector<vector<vector<sth>>> S;
S.resize(20);
for (i=0 to 19)
   S[i].resize(4);

Then in your main loop you can resize your third dimension for each value after your calculation:

for(j=0 to 19)
   for(m=0 to 3){
      //your calculation
      k=S[j][m].size();
      S[j][m].resize(k+1);
      S[j][m][k]=value;
   }

how to define two dimensional vector which element is vector of variable size?

1 Answers1