60 lines
1.8 KiB
Java
60 lines
1.8 KiB
Java
import java.math.BigInteger;
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import java.util.Arrays;
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class Test {
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final static int nMax = 250;
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final static int nBranches = 4;
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static BigInteger[] rooted = new BigInteger[nMax + 1];
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static BigInteger[] unrooted = new BigInteger[nMax + 1];
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static BigInteger[] c = new BigInteger[nBranches];
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static void tree(int br, int n, int l, int inSum, BigInteger cnt) {
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int sum = inSum;
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for (int b = br + 1; b <= nBranches; b++) {
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sum += n;
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if (sum > nMax || (l * 2 >= sum && b >= nBranches))
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return;
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BigInteger tmp = rooted[n];
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if (b == br + 1) {
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c[br] = tmp.multiply(cnt);
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} else {
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c[br] = c[br].multiply(tmp.add(BigInteger.valueOf(b - br - 1)));
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c[br] = c[br].divide(BigInteger.valueOf(b - br));
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}
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if (l * 2 < sum)
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unrooted[sum] = unrooted[sum].add(c[br]);
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if (b < nBranches)
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rooted[sum] = rooted[sum].add(c[br]);
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for (int m = n - 1; m > 0; m--)
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tree(b, m, l, sum, c[br]);
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}
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}
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static void bicenter(int s) {
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if ((s & 1) == 0) {
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BigInteger tmp = rooted[s / 2];
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tmp = tmp.add(BigInteger.ONE).multiply(rooted[s / 2]);
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unrooted[s] = unrooted[s].add(tmp.shiftRight(1));
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}
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}
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public static void main(String[] args) {
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Arrays.fill(rooted, BigInteger.ZERO);
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Arrays.fill(unrooted, BigInteger.ZERO);
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rooted[0] = rooted[1] = BigInteger.ONE;
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unrooted[0] = unrooted[1] = BigInteger.ONE;
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for (int n = 1; n <= nMax; n++) {
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tree(0, n, n, 1, BigInteger.ONE);
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bicenter(n);
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System.out.printf("%d: %s%n", n, unrooted[n]);
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}
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}
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}
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