import 'package:trotter/trotter.dart';

int chooseBestDistance(int t, int k, List<int> ls) {
 if((t>=0) && (k>=1) && (ls.length!=0)){
  var max = 0;
   var dist = 0;
    var combos = Combinations(k, ls);
    for (final combo in combos()) {
      for(int i=1; i<=k; i++){dist=dist+combo[i];}
      if ((dist>max) && (dist<=t) ){max = dist;}
    }

   if (max!=0 && (k<=ls.length)) {
     return max;
   }else{
    return -1;
    }
  }
}

void main(){
chooseBestDistance(174, 3, [51, 56, 58, 59, 61]); //173
chooseBestDistance(163, 3, [50]); // -1
}