| Description: |
This is multiple way do the division. But mainly focusing on Booth's Algorithms' and recursive methods using algorithm
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| Code 1: |
package com.kartik;
/**
*
* @author kartik
* Blog java2blogs.blogspot.com
* This is multiple way division algorithm. Mainly focusing on Booth's algorithms
*/
package com.kartik;
public class Division { public static final long division(int a, int b) { long result = ((long) a) / ((long) b); return result; } public static final long divisionUsingLoop(int a, int b) { int absoluteFirstData = Math.abs(a); int absoluteSecondData = Math.abs(b); long temp = absoluteFirstData; long result = 0; while (temp >= 0) { temp -= absoluteSecondData; if (temp >= 0) result++; } return (a > 0 && b > 0 || a < 0 && b < 0) ? result : -result; } public static final long divisionUsingRecursion(int a, int b) { int absoluteFirstData = Math.abs(a); int absoluteSecondData = Math.abs(b); long result = 1; int diff = absoluteFirstData - absoluteSecondData; if (diff > 0 && diff <= 1) { return result; } else if (diff < 0) { return 0; } result += divisionUsingRecursion(diff, absoluteSecondData); return (a > 0 && b > 0 || a < 0 && b < 0) ? result : -result; } public static final long divisionUsingMultiplication(int a, int b) { int absoluteFirstData = Math.abs(a); int absoluteSecondData = Math.abs(b); int temp = absoluteSecondData; int counter = 0; while (temp <= absoluteFirstData) { temp = temp << 1; counter++; } absoluteFirstData -= absoluteSecondData << (counter - 1); long result = (long) Math.pow(2, counter - 1); if (absoluteSecondData <= absoluteFirstData) result += divisionUsingMultiplication(absoluteFirstData, absoluteSecondData); return (a > 0 && b > 0 || a < 0 && b < 0) ? result : -result; } public static final long divisionUsingShift(int a, int b) { int absoluteFirstData = Math.abs(a); int absoluteSecondData = Math.abs(b); int tempA, tempB, counter; long result = 0L; while (absoluteFirstData >= absoluteSecondData) { tempA = absoluteFirstData >> 1; // Right shift "a" tempB = absoluteSecondData; counter = 1; while (tempA >= tempB) { // Double "tempB" until it's larger than // "tempA" tempB <<= 1; counter <<= 1; // Double the counter } absoluteFirstData -= tempB; // Subtract "tempB" from "a" result += counter; // Add counter (2^number of left shifts) } return (a > 0 && b > 0 || a < 0 && b < 0) ? result : -result; } public static final long divisionUsingLogs(int a, int b) { long absoluteFirstData = Math.abs(a); long absoluteSecondData = Math.abs(b); double logBase10A = Math.log10(absoluteFirstData); double logBase10B = Math.log10(absoluteSecondData); double powOf10 = Math.pow(10, (logBase10A - logBase10B)); long result = (long) Math.floor(powOf10); return (a > 0 && b > 0 || a < 0 && b < 0) ? result : -result; } } |
| Example 1 divisionUsingShift: |
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| Example 2 divisionUsingMultiplication with recursion: |
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I am Kartik Chandra Mandal from Bangalore, India. Working as software engineer in Java technology. Have good knowledge of OWASP and CSRF in security for applications and it's implementation in Java technology.