--- /dev/null
+#include "polynomial_adt.h"
+
+PolyAdt *create_adt(int hp)
+{
+ PolyAdt *pAdt = malloc(sizeof(PolyAdt));
+ assert(pAdt != NULL);
+
+ pAdt->head = NULL;
+ pAdt->terms = 0;
+ pAdt->hp = hp;
+
+ return pAdt;
+}
+
+void insert_term(PolyAdt *pAdt, float c, int e)
+{
+ assert(pAdt != NULL); //assume client code didnt call create_adt()
+ Node *n = malloc(sizeof(Node));
+
+ if(pAdt->head == NULL)
+ pAdt->head = create_node(c, e, pAdt->head);
+ else
+ for(n = pAdt->head; n->next != NULL; n = n->next); //go to the end of list
+ n->next = create_node(c, e, NULL);
+
+ pAdt->terms++;
+}
+
+PolyAdt *polyImage(const PolyAdt *orig)
+{
+ PolyAdt *img = create_adt(orig->hp);
+ Node *origHead = orig->head;
+
+ for(; origHead; origHead = origHead->next)
+ insert_term(img, origHead->coeff, origHead->exp);
+ return img;
+}
+
+PolyAdt *add(const PolyAdt *a, const PolyAdt *b)
+{
+ PolyAdt *sum;
+ Node *n, *np;
+ int state = 1;
+
+ assert(a != NULL && b != NULL);
+
+ int hpow = max(a->hp, b->hp);
+ sum = create_adt(hpow); //create space for it
+
+ /* using state machine to compare the poly with the most terms to
+ ** the poly with fewer, round robin type of effect comparison of
+ ** exponents => 3 Cases: Equal, Less, Greater
+ */
+ n = a->head; np = b->head;
+ while(state) {
+ /* compare the exponents */
+ if(n->exp == np->exp){
+ insert_term(sum, n->coeff + np->coeff, n->exp);
+ n = n->next;
+ np = np->next;
+ }
+
+ else if(n->exp < np->exp){
+ insert_term(sum, np->coeff, np->exp);
+ np = np->next; //move to next term of b
+ }
+
+ else { //greater than
+ insert_term(sum, n->coeff, n->exp);
+ n = n->next;
+ }
+ /* check whether at the end of one list or the other */
+ if(np == NULL && state){ //copy rest of a to sum
+ for(; n != NULL; n = n->next)
+ insert_term(sum, n->coeff, n->exp);
+ state = 0;
+ }
+
+ if(n == NULL && state){
+ for(; np != NULL; np = np->next)
+ insert_term(sum, np->coeff, np->exp);
+ state = 0;
+ }
+ }
+ return sum;
+}
+
+PolyAdt *subtract(const PolyAdt *a, const PolyAdt *b)
+{
+ assert(a != NULL && b != NULL);
+
+ PolyAdt *tmp = create_adt(b->hp);
+ Node *bptr;
+
+ for(bptr = b->head; bptr != NULL; bptr = bptr->next)
+ insert_term(tmp,-bptr->coeff,bptr->exp); //negating b's coeffs
+ return add(a,tmp);
+}
+
+PolyAdt *multiply(const PolyAdt *a, const PolyAdt *b)
+{
+ assert(a != NULL && b != NULL);
+
+ //the polys are inserted in order for now
+ PolyAdt *prod = create_adt(a->head->exp + b->head->exp);
+ Node *n = a->head, *np = b->head;
+ Node *t = b->head;
+
+ if(a->terms < b->terms){
+ n = b->head;
+ np = t = a->head;
+ }
+
+ for(; n != NULL; n = n->next){
+ np = t; //reset to the beginning
+ for(; np != NULL; np = np->next){ //always the least term in this loop
+ insert_term(prod, n->coeff * np->coeff, n->exp + np->exp);
+ }
+ }
+
+ return prod;
+}
+
+PolyAdt *derivative(const PolyAdt *a)
+{
+ assert(a != NULL);
+
+ PolyAdt *deriv = create_adt(a->head->exp - 1);
+ Node *n = a->head;
+
+ for(; n != NULL; n = n->next){
+ if(n->exp == 0) break;
+ insert_term(deriv, n->coeff * n->exp, n->exp-1);
+ }
+ return deriv;
+}
+
+PolyAdt *integrate(const PolyAdt *a)
+{
+ assert(a != NULL);
+
+ PolyAdt *integrand = create_adt(a->head->exp + 1);
+ Node *n;
+
+ for(n = a->head; n != NULL; n = n->next) //very simple term by term
+ insert_term(integrand, (float)n->coeff/(n->exp+1.0F), n->exp + 1);
+
+ return integrand;
+}
+
+void quadratic_roots(const PolyAdt *a, float *real, float *cplx)
+{
+ assert(a != NULL);
+
+ float dscrmnt, _a, b, c;
+ float u, v;
+
+ Node *n = a->head;
+ _a = n->coeff; b = n->next->coeff; c = n->next->next->coeff;
+
+ dscrmnt = (b*b) - 4*_a*c;
+ u = -b/(2*_a); v = sqrt((double)fabs(dscrmnt))/(2*_a);
+
+ if((real && !cplx) || (!real && cplx))
+ assert(1);
+
+ if(real == NULL && cplx == NULL){
+ if(a->hp != 2 && a->terms < 3){
+ printf("Invalid Quadratic*, A and B must be non-zero");
+ return;
+ }
+
+ if(dscrmnt != 0)
+ printf("X = %.2f +/- %.2f%c\n",u,v,dscrmnt < 0 ? 'I':' ');
+ else{
+ printf("(X %c %.2f)(X %c %.2f)\n",sgn(u),fabs(u),sgn(u),fabs(u));
+ printf("X1,2 = %.2f\n",u);
+ }
+ }
+ //save values in pointers
+ else {
+ if(dscrmnt < 0){ //x = u +/- vI Re(x) = u, Im(x) = +v
+ *real = u;
+ *cplx = v; //understand +/- is not representable
+ }
+ else if(dscrmnt == 0){
+ *real = u;
+ *cplx = 0.00F;
+ }
+ else{
+ *real = u + v;
+ *cplx = u - v;
+ }
+ }
+}
+
+PolyAdt *exponentiate(const PolyAdt *a, int n)
+{
+ assert(a != NULL);
+
+ PolyAdt *expn = create_adt(a->hp * n);
+ PolyAdt *aptr = polyImage(a);
+ int hl = n / 2;
+
+ //check default cases before calculation
+ if(n == 0){
+ insert_term(expn, 1, 0);
+ return expn;
+ }
+ else if(n == 1){
+ return aptr;
+ }
+
+ for(; hl ; hl--)
+ aptr = multiply(aptr, aptr);
+
+ if(n % 2) //odd exponent do a^(n-1) * a = a^n
+ expn = multiply(aptr, a);
+ else
+ expn = aptr;
+ return expn;
+}
+
+PolyAdt *compose(const PolyAdt *p, const PolyAdt *q)
+{
+ assert(p && q);
+
+ PolyAdt *comp = create_adt(p->head->exp * q->head->exp);
+ PolyAdt *exp;
+
+ Node *pp = p->head;
+ Node *qq = q->head;
+
+ int swap = 0;
+
+ if(p->terms < q->terms){
+ pp = q->head;
+ qq = p->head;
+ swap = 1;
+ }
+
+ /* going through, exponentiate each term with the exponent of p */
+ for(; pp != NULL; pp = pp->next){
+ exp = exponentiate(swap ? p: q, pp->exp);
+ insert_term(comp, pp->coeff * exp->head->coeff, exp->head->exp);
+ }
+
+ return comp;
+}
+
+void destroy_poly(PolyAdt *poly)
+{
+ Node *ps = poly->head;
+ Node *tmp = NULL;
+ while(ps != NULL){
+ tmp = ps;
+ free(tmp);
+ ps = ps->next;
+ }
+ poly->hp = poly->terms = 0;
+ poly->head = NULL;
+}
+
+void display_poly(const PolyAdt *a)
+{
+ assert(a != NULL);
+ Node *n;
+
+ for(n = a->head; n != NULL; n = n->next){
+
+ n->coeff < 0 ? putchar('-') : putchar('+');
+ if(n->exp == 0)
+ printf(" %.2f ",fabs(n->coeff));
+ else if(n->coeff == 1)
+ printf(" X^%d ",n->exp);
+ else if(n->exp == 1)
+ printf(" %.2fX ",fabs(n->coeff));
+ else if(n->coeff == 0)
+ continue;
+ else
+ printf(" %.2fX^%d ",fabs(n->coeff),n->exp);
+ }
+ printf("\n\n");
+}
projects / ccan / blobdiff