The time complexity of the given JBC problem could be proven to be BOUNDS(CONSTANT, 152).

(0) Obligation:

Need to prove time_complexity of the following program:

/**
 * Example taken from "A Term Rewriting Approach to the Automated Termination
 * Analysis of Imperative Programs" (http://www.cs.unm.edu/~spf/papers/2009-02.pdf)
 * and converted to Java.
 */

public class PastaB4 {
    public static void main(String[] args) {
        Random.args = args;
        int x = Random.random();
        int y = Random.random();

        while (x > y) {
            int t = x;
            x = y;
            y = t;
        }
    }
}


public class Random {
  static String[] args;
  static int index = 0;

  public static int random() {
    String string = args[index];
    index++;
    return string.length();
  }
}

(1) JBCToGraph (BOTH CONCRETE BOUNDS(ID, ID) transformation)

Constructed TerminationGraph.

(2) Obligation:

Termination Graph based on JBC Program:
PastaB4.main([Ljava/lang/String;)V: Graph of 177 nodes with 0 SCCs.

(3) TerminationGraphToComplexityProof (EQUIVALENT transformation)

Proven constant complexity by absence of SCCs and edges with non-constant weight

(4) BOUNDS(CONSTANT, 152)