Added P10081.

Author: LasseD

P10081.java

@@ -0,0 +1,49 @@
+import java.math.*;
+import java.util.Scanner;
+
+public class P10081 {
+    public static void main(String[] args) throws Exception {
+	BigInteger HUNDRED = BigInteger.valueOf(100);
+	String ret[][] = new String[8][101];
+
+	BigInteger tight[][] = new BigInteger[10][101]; // 0..k, n
+
+	for(int k = 2; k <= 9; ++k) {
+	    BigInteger KPLUSONE = BigInteger.valueOf(k+1);
+	    
+	    for(int i = 0; i <= k; ++i)
+		tight[i][1] = BigInteger.ONE; // One string of length 1 ends with i.
+	    BigInteger ALL = KPLUSONE;
+	    
+	    for(int n = 2; n <= 100; ++n) {
+		BigInteger SUM = BigInteger.ZERO;
+		for(int i = 0; i <= k; ++i) {
+		    tight[i][n] = tight[i][n-1];
+		    if(i > 0)
+			tight[i][n] = tight[i][n].add(tight[i-1][n-1]);
+		    if(i < k)
+			tight[i][n] = tight[i][n].add(tight[i+1][n-1]);
+		    SUM = SUM.add(tight[i][n]);
+		}
+
+		// set ret:
+		ALL = ALL.multiply(KPLUSONE);
+		BigDecimal N = new BigDecimal(SUM.multiply(HUNDRED));
+		BigDecimal D = new BigDecimal(ALL);
+		ret[k-2][n] = N.divide(D, 5, BigDecimal.ROUND_HALF_UP).toPlainString();
+
+	    }
+	}
+	
+	Scanner s = new Scanner(System.in);
+	while(s.hasNext()) {
+	    int k = s.nextInt();
+	    int n = s.nextInt();
+	    if(k <= 1 || n <= 1)
+		System.out.println("100.00000");
+	    else
+		System.out.println(ret[k-2][n]);
+	}
+	
+    }
+}

keywords.txt

@@ -1036,6 +1036,9 @@ Trivial circle slicing.
 P10080.cpp: Gopher II
 Use Modified Ford-Fulkerson for Maximum Bipartite Matching: http://www.geeksforgeeks.org/maximum-bipartite-matching/
 
+P10081.java: Tight Words
+BigDecimal, percentage fraction.
+
 P10082.cpp: WERTYU
 Char substitution, use string to build substitution array.