algorithm - Tabu Search in TSPTW -

i applied tabu search in tsptw problem, gives me result similar getting best improvement using exchanging pivot rule (exchange between 2 cities ), in papers, stated tabu gives result near optimal 1 (i have best solution of same initial solution 0 constraints violation using algorithm). sure, result normal ?, , here's pseudo code of applying tabu:

running tabu number of iteration tabu tenure=7 list tabulist each solution saved, 2 exchanged cities bestsol=initial solution currsol=initial solution tabufun() {    while(i<iteration)    {     i++;     currsol=bestneighbourhood(currsol)     if(currsol.fitness < bestsol.fitness)  // curr better best       bestsol=currsol   } return bestsol // result of tabu search }  bestneighbourhood(currsol) {   solutions=getallexchanepossiblesolution(currsol)   // if first time save global min, firsttime global variable set true  for(each sol in solutions) {    bestneigh=sol;    if(firsttime)   {       globalmin= sol.fitness       firsttime=false   } if(sol.fitness()<globalmin) {    globalmin=sol.fitness() }    check if cityi , cityj existing in tabulist    if not existing   {     //update elements in tabulist, element has tabu value=0 remove list     //and decrement tabu value of others     //add cityi , cityj in tabu list intial tabu value=tabu tenure     break;   }   else  {    //check aspiration    if(sol.fitness<globalmin)    {      //update tabu list      //reinitialize cityi , cityj tabu tenure    break;  } else  conitnue  }  return bestneigh 

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