feat: had fun with polynomials

1 files changed, 71 insertions, 0 deletions

diff --git a/custom/polynomial.py b/custom/polynomial.py
new file mode 100644
index 0000000..18fe8b6
--- /dev/null
+++ b/custom/polynomial.py
@@ -0,0 +1,71 @@
+import random
+class PolynomialTerm:
+    def __init__(self):
+        self.n = None
+        self.p = None
+    def strexpr(self):
+        return f"{self.n if self.n != 1 else ''}x^{self.p}"
+    def fromexpr(self, txt: str):
+        if txt[0] == 'x':
+            txt = '1'+ txt
+        #print(f"received {txt}")
+        l = txt.split("x^")
+        if len(l) != 2:
+            raise ValueError(l)
+        n_str: str = l[0]
+        p_str: str = l[1]
+        if (not n_str.isnumeric()) or (not p_str.isnumeric()):
+            raise ValueError(n_str)
+        self.n = int(n_str)
+        self.p = int(p_str)
+        return
+class Polynomial:
+    def __init__(self):
+        return
+    def fromexpr(self, strexpr: str):
+        #print(f"building with {strexpr}")
+        self.terms = []
+        for strterm in strexpr.split("+"):
+            #print(f"parsing {strterm}")
+            t = PolynomialTerm()
+            t.fromexpr(strterm)
+            #print(t.strexpr())
+            self.terms.append(t)
+        self.terms.sort(key=lambda x: x.p)
+    def strexpr(self):
+        return "+".join(list(map(lambda term: term.strexpr(), self.terms)))
+    def mul(self, other_poly):
+        poly = Polynomial()
+        ts = []
+        for t1 in self.terms:
+            for t2 in other_poly.terms:
+                nt = PolynomialTerm()
+                nt.n = t1.n * t2.n
+                nt.p = t1.p + t2.p
+                add = True
+                for t in ts:
+                    if nt.p == t.p:
+                        t.n += nt.n
+                        add = False
+                if not add: continue
+                ts.append(nt)
+        poly.terms = ts
+        return poly
+def test(limit: int):
+    for i in range(10):
+        p1 = Polynomial()
+        p2 = Polynomial()
+        str1 = ""
+        str2 = ""
+        n1 = random.randint(1, limit)
+        n2 = random.randint(1, limit)
+        for i in range(n1):
+            str1 += f"{random.randint(1, 10)}x^{random.randint(1, 10)}" + ("+" if i != n1-1 else "")
+            #print(str1)
+        for i in range(n2):
+            str2 += f"{random.randint(1, 10)}x^{random.randint(1, 10)}" + ("+" if i != n2-1 else "")
+        p1.fromexpr(str1)
+        p2.fromexpr(str2)
+        print(f"({p1.strexpr()}) * ({p2.strexpr()}) = {p1.mul(p2).strexpr()}")
+if __name__ == "__main__":
+    test(3)