101 lines
2.9 KiB
Java
101 lines
2.9 KiB
Java
import java.util.ArrayList;
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public class Polynomial {
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private int n;
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public Polynomial(int n) {
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this.n = n;
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}
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public ArrayList<Integer> normalize(ArrayList<Integer> w){
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for (int i = w.size()-1; i >= 0; --i){
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if (w.get(i).equals(0)) {
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w.remove(i);
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}else {
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return w;
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}
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}
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return w;
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}
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public ArrayList<Integer> multiply(ArrayList<Integer> f, ArrayList<Integer> g){
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ArrayList<Integer> result = new ArrayList<>();
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int tmp;
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for (int i = 0; i < f.size(); ++i){
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for (int j = 0; j < g.size(); ++j){
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tmp = f.get(i) * g.get(j);
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if (i + j < result.size()){
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tmp += result.get(i+j);
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result.set(i + j, tmp % n);
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} else {
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while ((i + j) >= (result.size())){
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result.add(0);
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}
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result.set(i + j, tmp % n);
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}
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}
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}
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return normalize(result);
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}
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public ArrayList<Integer> multiplyByConst(ArrayList<Integer> f, Integer a){
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ArrayList<Integer> result = new ArrayList<>();
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for (Integer i : f){
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result.add((i * a) % n);
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}
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return result;
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}
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public ArrayList<Integer> subtract(ArrayList<Integer> f, ArrayList<Integer> g){
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ArrayList<Integer> result = new ArrayList<>();
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for (int i = 0; i < f.size(); ++i){
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if (i < g.size()){
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result.add(Math.floorMod(f.get(i) - g.get(i), n));
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} else{
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result.add(f.get(i));
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}
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}
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return result;
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}
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private int getZero(int a, int b){
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int i = 0;
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while (true){
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if ((a + (-(b * i))) == 0){
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return i;
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}
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++i;
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}
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}
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public ArrayList<Integer> divide(ArrayList<Integer> f, ArrayList<Integer> g){
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ArrayList<Integer> quotient = new ArrayList<>();
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ArrayList<Integer> remainder = new ArrayList<>(f);
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ArrayList<Integer> tmpList;
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int a = f.size() - 1;
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int b = g.size() - 1;
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for (int i = 0; i < a - b + 1; ++i){
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quotient.add(0);
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}
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int q = quotient.size()-1;
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int tmp;
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while (a >= b) {
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tmp = getZero(remainder.get(a), g.get(b));
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quotient.set(q--, tmp);
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tmpList = multiplyByConst(g, tmp);
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while(tmpList.size() <= a) tmpList.add(0,0);
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remainder = subtract(remainder, tmpList);
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--a;
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}
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return normalize(remainder);
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}
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public ArrayList<Integer> nwd(ArrayList<Integer> f, ArrayList<Integer> g){
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if (g.size() == 0) return f;
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return nwd(g, divide(f, g));
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}
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}
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