c++ - Segmentation fault in LIS solution for Cracking the Coding interview 11.7 -

there problem in cracking coding interview -part v question 11.7 , solution trying implement here solution in java converted c++.but facing issue of segmentation fault.

#include<iostream> #include<vector> #include<algorithm>  using namespace std; class htwt {     public:         int ht;         int wt;         htwt(int ht,int wt):ht(ht),wt(wt){}         htwt(const htwt &other)         {             this->ht=other.ht;             this->wt=other.wt;         }         bool operator<(const htwt& obj) const         {             cout << __func__ << std::endl;             return (this->ht<obj.ht && this->wt<obj.wt);         } };  typedef vector<htwt> vhtwt; typedef vector<vhtwt > vvhtwt;  vhtwt& getseqwithmaxlen(vhtwt& seq1,vhtwt& seq2) {     cout << __func__ << std::endl;     if(seq1.empty())         return seq2;     if(seq2.empty())         return seq1;     return (seq1.size() > seq2.size() ? seq1 : seq2); }  void  lis(vhtwt& arr,vvhtwt& solutions,int current_index) {     cout << __func__ << std::endl;     if(current_index>arr.size()-1 || current_index<0)         return;     cout<<"arr.size()="<<arr.size()<<"current_index = "<<current_index<<endl;     htwt cur_element = arr[current_index];     /* find longest sequence can append current_element */     vhtwt best_sequence;     for(int i=0;i<current_index;i++)     {         cout<<"inside loop"<<endl;         if (arr[i]<cur_element)             best_sequence = getseqwithmaxlen(best_sequence,solutions[i]);             //cout<<"{"<<best_sequence[best_sequence.size()-1].ht<<","<<best_sequence[best_sequence.size()-1].wt<<"}"<<" ";     }     /* append current_element */     vhtwt new_solution;     if(!best_sequence.empty())         new_solution.insert(new_solution.end(),best_sequence.begin(),best_sequence.end());     new_solution.push_back(cur_element);       /* add list , recurse */     solutions[current_index] = new_solution;     lis(arr,solutions,current_index+1); }  vhtwt lis(vhtwt& arr) {     cout << __func__ << std::endl;     vvhtwt solutions;     lis(arr,solutions,0);     vhtwt best_sequence;     for(int i=0;i<arr.size();i++)         best_sequence = getseqwithmaxlen(best_sequence,solutions[i]);     return best_sequence; }  vhtwt getlis(vhtwt& arr) {     cout << __func__ << std::endl;     // sort array either height or weight      sort(arr.begin(),arr.end());     return lis(arr); }  int main() {     htwt arr[] = {htwt(12, 13), htwt(11, 15), htwt(9, 20), htwt(20, 20), htwt(40, 21), htwt(8, 42)};     vhtwt varr(arr,arr+(sizeof(arr)/sizeof(arr[0])));     vhtwt result = getlis(varr);     for(int i=0;i<result.size();i++)         cout<<"{"<<result[i].ht<<","<<result[i].wt<<"}"<<" ";     cout<<endl;     return 0; } 

can please me tell why code crashing @ line

htwt cur_element = arr[current_index];   

the size of arr 6 , index 0 , there should not segmentation fault guess.

$ ./a.out  getlis operator< operator< operator< operator< operator< lis lis arr.size()=6current_index = 0 segmentation fault: 11 

you not getting segmentation fault @ line

htwt cur_element = arr[current_index]; at

solutions[current_index] = new_solution;

because solutions has not been initialized. change line

vvhtwt solutions; to

vvhtwt solutions(arr.size());