Project Euler/63 - Revision history

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2019-10-09T03:49:30Z

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← Older revision		Revision as of 03:49, 9 October 2019
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	</pre>		</pre>

	Link: https://charlesreid1.com~~:3000~~/cs/euler/src/master/scratch/Round2_050-070/063/Problem063.java		Link: https://git.charlesreid1.com/cs/euler/src/master/scratch/Round2_050-070/063/Problem063.java

	==Flags==		==Flags==

	{{ProjectEulerFlag}}		{{ProjectEulerFlag}}

2018-01-08T10:29:51Z

Code

← Older revision		Revision as of 10:29, 8 January 2018
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	</pre>		</pre>

	Link: https://charlesreid1.com:3000/cs/euler/src/master/scratch/Round2_050-070/063		Link: https://charlesreid1.com:3000/cs/euler/src/master/scratch/Round2_050-070/063/Problem063.java

	==Flags==		==Flags==

	{{ProjectEulerFlag}}		{{ProjectEulerFlag}}

2018-01-08T10:29:39Z

Code

← Older revision		Revision as of 10:29, 8 January 2018
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	==Code==		==Code==

			Here is the full solution method - quite simple compared to some of the other Project Euler problems in the 60s range:

			<pre>
			public static void solve() {

			// These are the only numbers that qualify,
			// since 10^n is n+1 digits
			int counter = 0;
			for(int i=1; i<10; i++) {

			for(int j=1; j<25; j++) {
			int ndigits = (int)(Math.ceil(j*Math.log10(i)));
			boolean jDigits = (ndigits==j);
			if(jDigits) {
			counter++;
			}

			}
			}
			// This doesn't count 0^1, which is 0, also 1 digit.
			counter++;

			System.out.println(counter);

			}
			</pre>

	Link: https://charlesreid1.com:3000/cs/euler/src/master/scratch/Round2_050-070/063		Link: https://charlesreid1.com:3000/cs/euler/src/master/scratch/Round2_050-070/063

2018-01-08T10:29:06Z

Solution Technique

← Older revision		Revision as of 10:29, 8 January 2018
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	==Solution Technique==		==Solution Technique==

			This one is almost embarrassingly easy...

			To check if a number <math>a^b</math> is <math>b</math> digits, we can take <math>\log_{10}(b)</math> and if the value, rounded up, is <math>b</math>, our criteria is met.

			For this particular problem, we can stop at <math>n=25</math>, since <code>ceil(log10(9**25)) = 25</code>

	==Code==		==Code==

2018-01-08T10:26:59Z

Problem Statement

← Older revision		Revision as of 10:26, 8 January 2018
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	==Problem Statement==		==Problem Statement==

			How many n-digit positive integers exist which are also an nth power?

	Link: https://projecteuler.net/problem=63		Link: https://projecteuler.net/problem=63

2018-01-08T10:13:51Z

Code

← Older revision		Revision as of 10:13, 8 January 2018
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	==Code==		==Code==

			Link: https://charlesreid1.com:3000/cs/euler/src/master/scratch/Round2_050-070/063

	==Flags==		==Flags==

	{{ProjectEulerFlag}}		{{ProjectEulerFlag}}

2018-01-08T10:11:20Z

Created page with "==Problem Statement== Link: https://projecteuler.net/problem=63 ==Solution Technique== ==Code== ==Flags== {{ProjectEulerFlag}}"

New page

==Problem Statement==

Link: https://projecteuler.net/problem=63

==Solution Technique==

==Code==

==Flags==

{{ProjectEulerFlag}}