Data update

Task/Own-digits-power-sum/Java/own-digits-power-sum.java

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+import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
+
+public final class OwnDigitsPowerSum {
+
+	public static void main(String[] args) {
+		List<Integer> powers = IntStream.rangeClosed(0, 9).boxed().map( i -> i * i ).collect(Collectors.toList());
+		
+		System.out.println("Own digits power sums for N = 3 to 9 inclusive:");
+
+	    for ( int n = 3; n <= 9; n++ ) {
+	        for ( int d = 2; d <= 9; d++ ) {
+	            powers.set(d, powers.get(d) * d);
+	        }
+	
+	        long number = (long) Math.pow(10, n - 1);
+	        long maximum = number * 10;
+	        int lastDigit = 0;
+	        int sum = 0;
+	
+	        while ( number < maximum ) {
+	            if ( lastDigit == 0 ) {
+	            	sum = String.valueOf(number)
+	            		.chars().map(Character::getNumericValue).map( i -> powers.get(i) ).sum();
+	            } else if ( lastDigit == 1 ) {
+	                sum += 1;
+	            } else {
+	                sum += powers.get(lastDigit) - powers.get(lastDigit - 1);
+	            }
+	
+	            if ( sum == number ) {
+	                System.out.println(number);
+	                if ( lastDigit == 0 ) {
+	                    System.out.println(number + 1);
+	                }
+	                number += 10 - lastDigit;
+	                lastDigit = 0;
+	            } else if ( sum > number ) {
+	                number += 10 - lastDigit;
+	                lastDigit = 0;
+	            } else if ( lastDigit < 9 ) {
+	                number += 1;
+	                lastDigit += 1;
+	            } else {
+	                number += 1;
+	                lastDigit = 0;
+	            }	
+	        }	
+	    }
+	}
+
+}