58 lines
1.4 KiB
Java
58 lines
1.4 KiB
Java
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/*
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This is a Java Program to Implement Repeated Squaring Algorithm. Repeated squaring algorithm is used to compute xn efficiently.
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*/
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/**
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** Java Program to Implement Repeated Squaring Algorithm
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**/
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import java.util.Scanner;
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/** Class RepeatedSquaring **/
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public class RepeatedSquaring
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{
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/** Function for repeated squaring **/
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public double expBySquaring(double x, int n)
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{
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if (n < 0)
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return expBySquaring(1 / x, -n);
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else if (n == 0)
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return 1;
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else if (n == 1)
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return x;
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else if (n % 2 == 0)
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return expBySquaring(x * x, n / 2);
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else
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return x * expBySquaring(x * x, (n - 1)/2);
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}
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/** Main function **/
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public static void main (String[] args)
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{
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Scanner scan = new Scanner(System.in);
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System.out.println("Repeated Squaring Algorithm Test\n");
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/** Make an object of RepeatedSquaring class **/
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RepeatedSquaring rs = new RepeatedSquaring();
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/** Accept n , k **/
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System.out.println("\nEnter n and k of (N ^ K)");
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double n = scan.nextDouble();
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int k = scan.nextInt();
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double result = rs.expBySquaring(n, k);
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System.out.println("\nResult : "+ result);
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}
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}
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/*
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Enter n and k of (N ^ K)
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3 19
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Result : 1.162261467E9
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Repeated Squaring Algorithm Test
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Enter n and k of (N ^ K)
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7 -4
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Result : 4.1649312786339016E-4
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