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Ver2 Karatsuba

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Reborn 2025-03-10 16:56:00 +00:00
parent e87228dc11
commit 6e4f2d3119
2 changed files with 29 additions and 75 deletions
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102
Course Activities/02 - Core CS/05 - Core theory/01 - Divide and Conquer, Sorting and Searching, and Randomized Algorithm/Karatsuba/KaratsubaImplementation/src/main/java/karatsuba/Karatsuba.java
View File

@ -3,39 +3,16 @@ package karatsuba;
public class Karatsuba {
public int multiply(int x, int y) {
int xSize = Integer.toString(x).length();
int ySize = Integer.toString(y).length();
int n = xSize;
if (ySize > xSize) {
n = ySize;
}
if (xSize==1 && ySize==1) {
if (x < 10 && y < 10) {
return x*y;
}
int a;
int b;
int c;
int d;
int[] splitX = new int[2];
int[] splitY = new int[2];
if (xSize > 1) {
splitX = intFragmenter(x);
a = splitX[0];
b = splitX[1];
} else {
a = 0;
b = x;
}
if (ySize > 1) {
splitY = intFragmenter(y);
c = splitY[0];
d = splitY[1];
} else {
c = 0;
d = y;
}
String[] xyStr = intNormalizer(x, y);
int n = xyStr[0].length();
int[] abcd = intFragmenter(xyStr, n);
int a = abcd[0];
int b = abcd[1];
int c = abcd[2];
int d = abcd[3];
int ac = multiply(a, c);
int bd = multiply(b, d);
@ -48,70 +25,49 @@ public class Karatsuba {
return firstFactor + secondFactor + bd;
}
public int[] intFragmenter(int numb) {
String numbStr = Integer.toString(numb);
int numbSize = numbStr.length();
boolean sizeIsEven = this.isEven(numbSize);
int strHalfPoint = numbSize/2;
if (numbSize==1) {
return null;
}
if (!sizeIsEven) {
strHalfPoint = (numbSize-1)/2;
}
return this.parseStringIntoTwoIntArray(numbStr, strHalfPoint);
public int[] intFragmenter(String[] xyStr, int n) {
int strHalfPoint = n/2;
if (strHalfPoint == 1) {
int a = Integer.parseInt(String.valueOf(xyStr[0].charAt(0)));
int b = Integer.parseInt(String.valueOf(xyStr[0].charAt(1)));
int c = Integer.parseInt(String.valueOf(xyStr[1].charAt(0)));
int d = Integer.parseInt(String.valueOf(xyStr[1].charAt(1)));
return new int[] {a, b, c, d};
}
int a = Integer.parseInt(xyStr[0].substring(0, strHalfPoint-1));
int b = Integer.parseInt(xyStr[0].substring(strHalfPoint));
int c = Integer.parseInt(xyStr[1].substring(0, strHalfPoint-1));
int d = Integer.parseInt(xyStr[1].substring(strHalfPoint));
return new int[] {a, b, c, d};
}
public int intFragmenter(int x, int y) {
// This method exists to add left zeroes to the strings to make their size even and equal
public String[] intNormalizer(int x, int y) {
String xStr = Integer.toString(x);
String yStr = Integer.toString(y);
return 0;
}
public String[] stringNormalizer(String xStr, String yStr) {
// This method exists to add left zeroes to the strings to make their size even and equal
int xSize = xStr.length();
int ySize = yStr.length();
while (!isEven(xSize) || !isEven(ySize) || xSize != ySize) {
if (!isEven(xSize) || (xSize > ySize)) {
if (!isEven(xSize) || (xSize < ySize)) {
xStr = addLeftZero(xStr);
xSize = xStr.length();
}
if (!isEven(ySize) || (ySize > xSize)) {
if (!isEven(ySize) || (ySize < xSize)) {
yStr = addLeftZero(yStr);
ySize = yStr.length();
}
xSize = xStr.length();
ySize = yStr.length();
}
return new String[] {xStr, yStr};
}
public String addLeftZero(String str) {
return "";
return "0" + str;
}
public boolean isEven(int numb) {
if (numb/2==0) {
return false;
}
return true;
}
public int[] parseStringIntoTwoIntArray(String str, int strHalfPoint) {
int a;
int b;
if (strHalfPoint == 1) {
a = Integer.parseInt(String.valueOf(str.charAt(0)));
b = Integer.parseInt(String.valueOf(str.charAt(1)));
} else {
a = Integer.parseInt(str.substring(0, strHalfPoint-1));
b = Integer.parseInt(str.substring(strHalfPoint));
}
return new int[] {a, b};
}
}

2
Course Activities/02 - Core CS/05 - Core theory/01 - Divide and Conquer, Sorting and Searching, and Randomized Algorithm/Karatsuba/KaratsubaImplementation/src/main/java/karatsuba/Main.java
View File

@ -8,7 +8,5 @@ public class Main {
Karatsuba karatsuba = new Karatsuba();
int result = karatsuba.multiply(x, y);
System.out.println(result);
}
}