extend gcd and pairs

iTitus · Dec 13, 2020 · 14a0ac0 · 14a0ac0
1 parent 9a82ad3
commit 14a0ac0
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Showing 10 changed files with 472 additions and 89 deletions.
diff --git a/src/main/java/io/github/ititus/data/pair/IntIntPair.java b/src/main/java/io/github/ititus/data/pair/IntIntPair.java
@@ -0,0 +1,48 @@
+package io.github.ititus.data.pair;
+
+import io.github.ititus.data.ArrayUtil;
+
+public final class IntIntPair {
+
+    private final int a;
+    private final int b;
+
+    private IntIntPair(int a, int b) {
+        this.a = a;
+        this.b = b;
+    }
+
+    public int a() {
+        return a;
+    }
+
+    public int b() {
+        return b;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (!(o instanceof IntIntPair)) {
+            return false;
+        }
+        IntIntPair that = (IntIntPair) o;
+        return a == that.a && b == that.b;
+    }
+
+    @Override
+    public int hashCode() {
+        return ArrayUtil.hash(a, b);
+    }
+
+    @Override
+    public String toString() {
+        return "<" + a + "," + b + ">";
+    }
+
+    public static IntIntPair of(int a, int b) {
+        return new IntIntPair(a, b);
+    }
+}
diff --git a/src/main/java/io/github/ititus/data/pair/LongLongPair.java b/src/main/java/io/github/ititus/data/pair/LongLongPair.java
@@ -0,0 +1,48 @@
+package io.github.ititus.data.pair;
+
+import io.github.ititus.data.ArrayUtil;
+
+public final class LongLongPair {
+
+    private final long a;
+    private final long b;
+
+    private LongLongPair(long a, long b) {
+        this.a = a;
+        this.b = b;
+    }
+
+    public long a() {
+        return a;
+    }
+
+    public long b() {
+        return b;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (!(o instanceof LongLongPair)) {
+            return false;
+        }
+        LongLongPair that = (LongLongPair) o;
+        return a == that.a && b == that.b;
+    }
+
+    @Override
+    public int hashCode() {
+        return ArrayUtil.hash(a, b);
+    }
+
+    @Override
+    public String toString() {
+        return "<" + a + "," + b + ">";
+    }
+
+    public static LongLongPair of(long a, long b) {
+        return new LongLongPair(a, b);
+    }
+}
diff --git a/...main/java/io/github/ititus/data/Pair.java → ...java/io/github/ititus/data/pair/Pair.java b/...main/java/io/github/ititus/data/Pair.java → ...java/io/github/ititus/data/pair/Pair.java
@@ -1,9 +1,8 @@
-package io.github.ititus.data;
+package io.github.ititus.data.pair;
 
-import java.util.Map;
 import java.util.Objects;
 
-public final class Pair<A, B> implements Printable {
+public final class Pair<A, B> {
 
     private final A a;
     private final B b;
@@ -17,11 +16,19 @@ public static <A, B> Pair<A, B> of(A a, B b) {
         return new Pair<>(a, b);
     }
 
-    public A getA() {
+    public static IntIntPair of(int a, int b) {
+        return IntIntPair.of(a, b);
+    }
+
+    public static LongLongPair of(long a, long b) {
+        return LongLongPair.of(a, b);
+    }
+
+    public A a() {
         return a;
     }
 
-    public B getB() {
+    public B b() {
         return b;
     }
 
@@ -42,19 +49,8 @@ public int hashCode() {
         return Objects.hash(a, b);
     }
 
-    @Override
-    public String getPrefix() {
-        return "Pair";
-    }
-
-    @Override
-    public void getPrintableFields(Map<String, String> fields) {
-        fields.put("a", Objects.toString(a));
-        fields.put("b", Objects.toString(b));
-    }
-
     @Override
     public String toString() {
-        return Printable.toPrintableString(this);
+        return "<" + a + "," + b + ">";
     }
 }
diff --git a/src/main/java/io/github/ititus/math/number/BigIntegerMath.java b/src/main/java/io/github/ititus/math/number/BigIntegerMath.java
@@ -1,12 +1,13 @@
 package io.github.ititus.math.number;
 
-import io.github.ititus.math.time.StopWatchStatistics;
-
 import java.math.BigInteger;
 import java.util.Map;
 import java.util.NavigableMap;
 import java.util.TreeMap;
 
+import static java.math.BigInteger.ONE;
+import static java.math.BigInteger.ZERO;
+
 public final class BigIntegerMath {
 
     public static final BigInteger THREE = of(3);
@@ -15,7 +16,6 @@ public final class BigIntegerMath {
     public static final BigInteger MINUS_ONE = of(-1);
 
     private static final NavigableMap<BigInteger, BigInteger> FACTORIAL_CACHE = new TreeMap<>();
-    private static final StopWatchStatistics gcdTime = StopWatchStatistics.arithmetic();
 
     private BigIntegerMath() {
     }
@@ -34,20 +34,20 @@ public static BigInteger of(String n) {
 
     @SuppressWarnings("Duplicates")
     public static BigInteger pow(BigInteger base, BigInteger exponent) {
-        if (base.equals(BigInteger.ONE) || exponent.signum() == 0) {
-            return BigInteger.ONE;
+        if (base.equals(ONE) || exponent.signum() == 0) {
+            return ONE;
         } else if (base.signum() == 0) {
-            return BigInteger.ZERO;
+            return ZERO;
         } else if (exponent.signum() < 0) {
             throw new ArithmeticException();
         }
 
-        BigInteger n = BigInteger.ONE;
+        BigInteger n = ONE;
 
         while (exponent.signum() > 0) {
             if (BigIntegerMath.isOdd(exponent)) {
                 n = n.multiply(base);
-                exponent = exponent.subtract(BigInteger.ONE);
+                exponent = exponent.subtract(ONE);
             } else {
                 base = base.multiply(base);
                 exponent = exponent.shiftRight(1);
@@ -58,31 +58,48 @@ public static BigInteger pow(BigInteger base, BigInteger exponent) {
     }
 
     public static BigInteger gcd(BigInteger a, BigInteger b) {
-        //gcdTime.start();
-        BigInteger gcd;
-        if (a.signum() == 0) {
-            gcd = b.abs();
-        } else if (b.signum() == 0 || a.equals(b)) {
-            gcd = a.abs();
-        } else if (a.equals(BigInteger.ONE) || b.equals(BigInteger.ONE)) {
-            gcd = BigInteger.ONE;
-        } /*else if (!isProbablePrime(a, 10) && !isProbablePrime(a, 10)) {
-            gcd = a.gcd(b);
-        }*/ else { // a or b might be prime
-            gcd = a.gcd(b);
+        if (a.equals(ONE) || b.equals(ONE)) {
+            return ONE;
         }
-        //System.out.println("gcd: " + gcdTime.stop());
-        return gcd;
+
+        return a.gcd(b);
     }
 
     public static BigInteger lcm(BigInteger a, BigInteger b) {
-        if (a.equals(BigInteger.ZERO) || b.equals(BigInteger.ZERO)) {
+        if (a.equals(ZERO) || b.equals(ZERO)) {
             throw new ArithmeticException();
         }
 
         return a.divide(gcd(a, b)).multiply(b).abs();
     }
 
+    public static ExtendedGdcBigIntegerResult extendedGcd(BigInteger a, BigInteger b) {
+        BigInteger old_r = a.abs();
+        BigInteger r = b.abs();
+        BigInteger old_s = ONE;
+        BigInteger s = ZERO;
+        BigInteger old_t = ZERO;
+        BigInteger t = ONE;
+
+        while (r.signum() != 0) {
+            BigInteger q = old_r.divide(r);
+
+            BigInteger tmp = r;
+            r = old_r.subtract(q.multiply(r));
+            old_r = tmp;
+
+            tmp = s;
+            s = old_s.subtract(q.multiply(s));
+            old_s = tmp;
+
+            tmp = t;
+            t = old_t.subtract(q.multiply(t));
+            old_t = tmp;
+        }
+
+        return new ExtendedGdcBigIntegerResult(old_r, old_s, old_t);
+    }
+
     public static boolean isOdd(BigInteger n) {
         return n.testBit(0);
     }
@@ -102,7 +119,7 @@ public static boolean isProbablePrime(BigInteger n, int certainty) {
     public static boolean isPrime(BigInteger n) {
         if (n.signum() <= 0) {
             throw new IllegalArgumentException();
-        } else if (n.equals(BigInteger.ONE)) {
+        } else if (n.equals(ONE)) {
             return false;
         } else if (isEven(n)) {
             return false;
@@ -112,7 +129,7 @@ public static boolean isPrime(BigInteger n) {
     }
 
     public static boolean isPowerOf2(BigInteger n) {
-        return n.signum() != 0 && n.and(n.subtract(BigInteger.ONE)).signum() == 0;
+        return n.signum() != 0 && n.and(n.subtract(ONE)).signum() == 0;
     }
 
     public static boolean isInt(BigInteger n) {
@@ -125,25 +142,25 @@ public static boolean isLong(BigInteger n) {
 
     public static BigInteger binomial(BigInteger n, BigInteger k) {
         if (k.signum() < 0 || k.compareTo(n) > 0) {
-            return BigInteger.ZERO;
+            return ZERO;
         } else if (k.signum() == 0 || n.equals(k)) {
-            return BigInteger.ONE;
+            return ONE;
         }
 
         k = k.min(n.subtract(k));
 
-        BigInteger result = BigInteger.ONE;
-        BigInteger product = BigInteger.ONE;
-        for (BigInteger i = BigInteger.ONE; i.compareTo(k) <= 0; i = i.add(BigInteger.ONE)) {
+        BigInteger result = ONE;
+        BigInteger product = ONE;
+        for (BigInteger i = ONE; i.compareTo(k) <= 0; i = i.add(ONE)) {
             product = product.multiply(i);
             result = result.multiply(n.subtract(k).add(i));
         }
         return result.divide(product);
     }
 
     public static BigInteger multinomial(BigInteger... n) {
-        BigInteger result = BigInteger.ONE;
-        BigInteger sum = BigInteger.ZERO;
+        BigInteger result = ONE;
+        BigInteger sum = ZERO;
         for (BigInteger n_i : n) {
             sum = sum.add(n_i);
             result = result.multiply(binomial(sum, n_i));
@@ -154,13 +171,13 @@ public static BigInteger multinomial(BigInteger... n) {
     public static BigInteger factorial(BigInteger n) {
         if (n.signum() < 0) {
             throw new ArithmeticException();
-        } else if (n.signum() == 0 || n.equals(BigInteger.ONE)) {
-            return BigInteger.ONE;
+        } else if (n.signum() == 0 || n.equals(ONE)) {
+            return ONE;
         }
 
         Map.Entry<BigInteger, BigInteger> maxEntry = FACTORIAL_CACHE.lastEntry();
-        BigInteger maxN = maxEntry != null ? maxEntry.getKey() : BigInteger.ONE;
-        BigInteger result = maxEntry != null ? maxEntry.getValue() : BigInteger.ONE;
+        BigInteger maxN = maxEntry != null ? maxEntry.getKey() : ONE;
+        BigInteger result = maxEntry != null ? maxEntry.getValue() : ONE;
 
         if (maxN.equals(n)) {
             return result;
@@ -169,7 +186,7 @@ public static BigInteger factorial(BigInteger n) {
         }
 
         while (maxN.compareTo(n) < 0) {
-            maxN = maxN.add(BigInteger.ONE);
+            maxN = maxN.add(ONE);
             result = result.multiply(maxN);
             FACTORIAL_CACHE.put(maxN, result);
         }

diff --git a/src/main/java/io/github/ititus/math/number/BigRationalMath.java b/src/main/java/io/github/ititus/math/number/BigRationalMath.java
@@ -1,12 +1,9 @@
 package io.github.ititus.math.number;
 
 import io.github.ititus.math.function.PowerSeriesCalculator;
-import io.github.ititus.math.time.DurationFormatter;
-import io.github.ititus.math.time.StopWatch;
 
 import java.math.BigDecimal;
 import java.math.BigInteger;
-import java.time.Duration;
 
 import static io.github.ititus.math.number.BigRational.of;
 import static io.github.ititus.math.number.BigRationalConstants.*;
@@ -100,38 +97,8 @@ public static BigRational ln(BigRational x) {
             return ZERO;
         }
 
-        StopWatch w = StopWatch.createRunning();
-
         BigRational lnFast = PowerSeriesCalculator.lnFast(x);
-
-        Duration d = w.stop();
-        System.out.println("lnFast: " + DurationFormatter.formatMillis(d));
-        w.start();
-
-        BigRational exp = lnFast.exp();
-
-        d = w.stop();
-        System.out.println("exp: " + DurationFormatter.formatMillis(d));
-        w.start();
-
-        BigRational newX = x.divide(exp);
-
-        d = w.stop();
-        System.out.println("div: " + DurationFormatter.formatMillis(d));
-        w.start();
-
-        BigRational ln = PowerSeriesCalculator.ln(newX);
-
-        d = w.stop();
-        System.out.println("ln: " + DurationFormatter.formatMillis(d));
-        w.start();
-
-        BigRational realLn = lnFast.add(ln);
-
-        d = w.stop();
-        System.out.println("add: " + DurationFormatter.formatMillis(d));
-
-        return realLn;
+        return lnFast.add(PowerSeriesCalculator.ln(x.divide(lnFast.exp())));
     }
 
     public static BigRational sin(BigRational x) {