Calc precise result of \(n\)th power of two
% calc the precise result of 2^167.
clear all; clear;
N = 167;
result_len = floor(log10(2^N))+1; % calc the digit of the result
result = zeros(1, result_len); % create a blank matrix to store the result
result(1) = 1; % 2^0 initialized result
str_result = cell(1,N); % create N string cell to store the result of every step
last = 1; % initialized the digit of the result
fid =fopen('result.txt','w'); % create a file (result.txt) to print the result
fprintf(fid,['## result of 2^', num2str(N),'\n']);
%
for idx = 1:N
% multiply by 2 in every step
result = result * 2;
for k = 1:last
% advances to the higher one for every decimal one
result(k+1) = result(k+1) + mod(floor(result(k)/10),10);
result(k) = mod(result(k),10);
% store the digit of the result
if(result(k+1) ~= 0)
last = k + 1;
end
end
% store the result via string
str_result{idx} = strrep(num2str(result(last:-1:1)),' ', '');
% print the result to the file (result.txt)
fprintf(fid,['2^', num2str(idx),' = %s\n'],str_result{idx});
end
fclose(fid);
% display the finnal result
disp(['2^', num2str(idx),' = ', str_result{end}]);
Command Window
2^167 = 187072209578355573530071658587684226515959365500928
/**
* The CalcApp class implements an application that
* simply prints result to standard output.
*/
import java.math.*;
import java.io.*;
class CalcApp {
public static void main(String[] args) {
// System.out.println("2^167=");
BigInteger a = new BigInteger("2");
File f = new File("result_of_pow(2,167).txt");
try{
FileOutputStream fos1=new FileOutputStream(f);
OutputStreamWriter dos1=new OutputStreamWriter(fos1);
for(int i = 1; i < 168; i++){
dos1.write("2^"+i+" = "+ a.pow(i) + "\n");
}
System.out.println("2^167 = "+ a.pow(167)); // Display the result.
dos1.close();
}
catch(IOException e){
System.out.println("Eorror" + e);
}
}
}
Terminal
$ javac CalcApp.java && java CalcApp
2^167 = 187072209578355573530071658587684226515959365500928