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POMethod that determines if a number is 'insipid'
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  1. POMethod that determines if a number is 'insipid'
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    copied!<p>So I have been tasked with writing a program that determines if a number is insipid or not. Meaning, if you take a number: 57 for example, and you add the square of each digit, 5*5 + 7*7, that is now the new number:74. And you keep doing that until you either get 58 which means the number is NOT insipid, or you get 1, meaning the number is. 58 will just repeat a sequence that always ends back on 58. </p> <p>So I wanted to attempt it with some basic recursion but perhaps I misunderstand the use of recursion here.</p> <p>Here are the two relevant methods I wrote:</p> <pre><code>public static boolean insipid(int num){ int dig1 = 0, dig2 = 0, dig3 = 0; // num = 159 for example, dig1 would be 1. Default is 0 in case of a 2 digit number, dig1*dig1 = 0 if(num == 58){ //The number is not insipid return false; } if(num == 1){ // the number is insipid return true; } if (num &lt; 10){ insipid(num * num); } if(num&gt;99){ dig1 = (int)(num / 100); dig2 = (int)((num - 100)/10); dig3 = num - (((int)(num / 10))*10); insipid(squaresum(dig1,dig2,dig3)); } else{ dig2 = (int)(num/10); //the 10s place dig3 = num - (((int)(num/10)) * 10); // the 1's place insipid(squaresum(dig1, dig2,dig3)); //dig1 = 0 so I just pass it along with it. } } public static int squaresum(int dig1, int dig2, int dig3){ //Returns the sum of three digits squared. return (dig1 * dig1) + (dig2 * dig2) + (dig3 + dig3); } </code></pre> <p>It gives me an error saying that Insipid() must return a boolean whenever I supply it a number. But I know for any number given it will <em>always</em> either eventually resolve to 58 or 1. So shouldn't true or false always eventually be returned so a boolean is returned and the error is invalid? Obviously this is not the case, but how I see it. Is it the use of the recursion here that is invalid?</p> <p>Also, if you have any suggestions on how I might clean this up I wouldn't mind harsh criticism, my java is not very good.</p>
 

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