java - How to sort a linked list of Polynomials by degree? -

currently i've written method adds 2 polynomials together. poly1 , poly2. logic of method follows, first adds matching degree terms poly1 , poly2, adds non-matching terms poly1, , adds non-matching terms poly2. because of this, terms out of order.

polynomial answer = new polynomial();      (node firstpoly = poly; firstpoly != null; firstpoly = firstpoly.next){         boolean polyadded = false;         (node secondpoly = p.poly; secondpoly != null; secondpoly = secondpoly.next){              if (firstpoly.term.degree == secondpoly.term.degree){              answer = addtorear(answer, (firstpoly.term.coeff + secondpoly.term.coeff), firstpoly.term.degree, null);                     if (answer.poly.term.coeff == 0){                         answer.poly = null;                     }                     polyadded = true;                        }           }         if (polyadded == false){         answer = addtorear(answer, firstpoly.term.coeff, firstpoly.term.degree, null);         if (answer.poly.term.coeff == 0){             answer.poly = null;         }         }      }      (node secondpoly = p.poly; secondpoly != null; secondpoly = secondpoly.next){         boolean match = false;         (node answerpoly = answer.poly; answerpoly != null; answerpoly = answerpoly.next){             if (secondpoly.term.degree == answerpoly.term.degree){                 match = true;                 break;             }          }         if (match == false){         answer = addtorear(answer, secondpoly.term.coeff, secondpoly.term.degree, null);         }     }      return answer;      //alt + shift + r } 

if code outputs:

8.0x^4 + 4.0x^5 + 2.0x^3 + -1.0x + 12.0

the linked list represented such:

(coefficient, degree) // (12, 0) -> (-1, 1) -> (2, 3) -> (4, 5) -> (8, 4)

i want sort answer polynomial order of degree. linked list should represented this:

(coefficient, degree) // (12, 0) -> (-1, 1) -> (2, 3) -> (8, 4) -> (4, 5)

edit: found solution on own. here sorting method created:

private polynomial sortbydegree(polynomial p){     node prev = p.poly;     node current = p.poly.next;      while (current != null){         if (current.term.degree < prev.term.degree){             int temp = current.term.degree;             current.term.degree = prev.term.degree;             prev.term.degree = temp;              float temp2 = current.term.coeff;             current.term.coeff = prev.term.coeff;             prev.term.coeff = temp2;              prev = p.poly;             current = p.poly.next;         }          prev = prev.next;         current = current.next;     }      return p; } 

thanks everyone!

can suggest 2 approaches:

first. fetch linked list array list (stack), sort array list, rebuild linked list.

second. use following algo:

void sortpoly(polynomial answer) {     float lowermargin = 0;     node head = null, tail = null;      while (answer.poly != null) {         node next = detouchmin(lowermargin, answer);         lowermargin = next.term.degree;          if (tail != null) {             tail.next = next;             tail = next;         else {             head = next;             tail = next;         }     }      answer.poly = head; }   node detouchmin(float lowermargin, polynomial answer) {     float min = float.inf;     node n = null;     node t = answer.poly;     while (t != null) {         if ((t.term.degree > lowermargin) && (t.term.degree < min)) {             n = t;             min = n.term.degree;         }         t = t.next;     }      if (n != null) {         node t = answer.poly, prev = null;         while (t != null) {             if (t == n) {                 if (prev != null)                     answer.poly = t.next;                 else                     prev.next = t.next;             }             prev = t;             t = t.next;         }     }      return n; } 

note: code not tested