49 lines
1.8 KiB
Java
49 lines
1.8 KiB
Java
import java.util.Arrays;
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import java.util.HashSet;
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public class VampireNumbers{
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private static int numDigits(long num){
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return Long.toString(Math.abs(num)).length();
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}
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private static boolean fangCheck(long orig, long fang1, long fang2){
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if(Long.toString(fang1).endsWith("0") && Long.toString(fang2).endsWith("0")) return false;
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int origLen = numDigits(orig);
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if(numDigits(fang1) != origLen / 2 || numDigits(fang2) != origLen / 2) return false;
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byte[] origBytes = Long.toString(orig).getBytes();
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byte[] fangBytes = (Long.toString(fang1) + Long.toString(fang2)).getBytes();
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Arrays.sort(origBytes);
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Arrays.sort(fangBytes);
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return Arrays.equals(origBytes, fangBytes);
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}
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public static void main(String[] args){
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HashSet<Long> vamps = new HashSet<Long>();
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for(long i = 10; vamps.size() <= 25; i++ ){
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if((numDigits(i) % 2) != 0) {i = i * 10 - 1; continue;}
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for(long fang1 = 2; fang1 <= Math.sqrt(i) + 1; fang1++){
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if(i % fang1 == 0){
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long fang2 = i / fang1;
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if(fangCheck(i, fang1, fang2) && fang1 <= fang2){
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vamps.add(i);
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System.out.println(i + ": [" + fang1 + ", " + fang2 +"]");
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}
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}
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}
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}
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Long[] nums = {16758243290880L, 24959017348650L, 14593825548650L};
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for(Long i : nums){
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for(long fang1 = 2; fang1 <= Math.sqrt(i) + 1; fang1++){
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if(i % fang1 == 0){
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long fang2 = i / fang1;
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if(fangCheck(i, fang1, fang2) && fang1 <= fang2){
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System.out.println(i + ": [" + fang1 + ", " + fang2 +"]");
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}
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}
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}
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}
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}
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}
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