Probléme d'execution

#include <iostream>
using namespace std ;

void echange (int &a ,int &b)
{
     int copie(a);
     a=b;
     b=copie;
     }
void tri_shell (int tab[],unsigned int taille) {
     for (unsigned int k(taille/2);k>=1;k/=2)
          for (unsigned i(k+1);i<=taille;++i) {
              int j(i-k);
              while (j>0){
                    if (tab[j-1] > tab[j+k-1]) {
                                 echange (tab[j-1],tab[j+k-1]);
                                 j-=k;
                                 }
                                 else {
                                      j=0;
                                      }
                                      }
                                      }
                                      }
 int main()
 {
     const unsigned int taille(12);
     int a_trier[taille]={4,5,2,6,4,2,1,8,-1,4,6,-1};
     for (unsigned int i(0);i<taille;++i)
     cout << a_trier[i] << endl ;
     tri_shell (a_trier,taille);
     cout <<"----------------"<< endl ;
     for (unsigned int i(0);i<taille ;++i)
     cout<< a_trier[i]<<endl ;
     
     return 0;
     }