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Problem solution · Java

CCC 2000 S4 - Golf

CCC 2000 S4 - Golf: a Java solution using direct simulation. Learn the idea, check the complexity, and read the full code, with credit to CCCSolutions.

Technique
Direct simulation
Source
CCCSolutions
Length
98 lines
Start with the idea.

Try the problem first. If you get stuck, read the approach below, then write your own solution. The full code is at the bottom.

Approach

Direct simulation

For CCC 2000 S4 - Golf, the implementation follows the problem’s operations directly while maintaining only the state needed for the next decision.

  1. Translate each rule into one explicit state update.
  2. Maintain the invariant after every processed item.
  3. Return the accumulated state once all relevant input has been handled.

Code notes

  • 98 lines of Java from the credited upstream file ccc00s4.java.
  • The implementation visibly relies on sequence storage.
  • 3 loop blocks detected.

Complexity

Count the number and nesting of passes over the input, then include the maintained containers in the memory estimate.

Check the problem constraints before deciding whether this complexity will pass.

Source

Code and credit

This code comes from CCCSolutions by CCCSolutions contributors · Milliken Mills High School and is used under the MIT licence.

Open problem ↗Original source ↗
Full codeCCC 2000 S4 - Golf · JavaJava
Use this to learn the idea, then write your own version.
// CCC 2000// Problem S4 Golf // This is a classic Dynamic programming problem// given a set of numbers(clubs), determine the total number of clubs// needed to get to a given distance. // (full solution giving the clubs themselves is in javapgms) // For example if there were clubs 2,4,5 and the total distance was 12// then it would take 3 clubs (5, 5 and 2) // method is calculate # for all distances from 0 to given!// F(0) = 0// F(n) = (minimum of F(n-club(i)) i=0 to #clubs, provided minimum >= 0) + 1 // using the above example of 2, 4 and 5 clubs you would have:// F(0) = 0// F(1) = -1   (can't get there)// F(2) = 1// F(3) = -1// F(4) = 1// F(5) = 1// F(6) = 2 because F(6-2) = 1 is min, therefore answer is F(4) + 1 = 2// F(7) = 2 because F(7-2) = 1 is min, therefore answer is F(5) + 1 = 2// F(8) = 2 because F(8-4) = 1 is min, therefore answer is F(4) + 1 = 2// F(9) = 2 because F(9-4) = 1 is min, therefore answer is F(5) + 1 = 2// F(10) = 2 because F(10-5) = 1 is min, therefore answer is F(5) + 1 = 2// F(11) = 3 because F(11-2) = 2 is min, therefore answer is F(9) + 1 = 3// F(12) = 3 because F(12-2) = 2 is min, therefore answer is F(10) + 1 = 3 // file consists of distance, number of clubs and then the clubs.// output is a statement about number of strokes, or "defeat" import java.awt.*;import hsa.*;  public class S4Golf{    static Console c;     public static void main (String [] args)    {	c = new Console ();	int club [] = new int [32];	int dis, n, ans; 	TextInputFile fi = new TextInputFile ("golf.in1");	TextOutputFile fo = new TextOutputFile ("golf.ou1"); 	dis = fi.readInt ();	n = fi.readInt ();	for (int i = 0 ; i < n ; i++)	    club [i] = fi.readInt ();	ans = solve (dis, club, n);	if (ans == -1)	{	    fo.println ("Roberta acknowledges defeat.");	    c.println ("Roberta acknowledges defeat.");	}	else	{	    fo.println ("Roberta wins in " + ans + " strokes.");	    c.println ("Roberta wins in " + ans + " strokes.");	}    }      public static int solve (int distance, int [] club, int n)    {	int [] f;	int min, t; 	f = new int [distance + 1]; 	f [0] = 0; 	for (int x = 1 ; x <= distance ; x++)	{	    min = 999999999;	    for (int j = 0 ; j < n ; j++)	    {		t = x - club [j];		if (t >= 0 && f [t] >= 0 && f [t] < min)		    min = f [t];	    }	    if (min < 999999999)		f [x] = min + 1;	    else		f [x] = -1;	}	return f [distance];    }}

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