memory - C++ calling one function repeatedly system hang -

i getting serious issue 1 function in c++. function

double** fun1(unsigned l,unsigned n, vector<int>& list,                     vector<string>& dataarray) {   double** array2d = 0;   array2d = new double*[l];        string alphabet="acgt";      (int = 0; < l; i++)   {         array2d[i] = new double [4];         vector<double> count(4, 0.0);         for(int j=0;j<n;++j)         {             for(int k=0;k<4;k++)             {                 if (toupper(dataarray[list[j]][i])==alphabet[k])                    count[k]=count[k]+1;             }          }      for(int k=0;k<4;k++)         array2d[i][k]=count[k];           count.clear();   }    return array2d; } 

the value of l around 100 , n=1, dataarray size (50000 x l) , list contain 1 number between 0-49999. calling function main program many number of times (may more 50 million times). upto number of times going smooth after 2/3 minute around system hangs. unable find problem code. guess memory getting short don't know why?

you missing corresponding delete[] code.

note [] means deleting array. if forget add these venturing undefined territory (3.7.4.2 in n3797).

you may wish try using std::array mitigate having new , delete[] much. if called as , loop small concerned coherency of data.