/****************************************************************************** * Compilation: javac RandomExpression.java * Execution: java RandomExpression p * * % java RandomExpression 0.25 * 2 * * % java RandomExpression 0.25 * ((38 + (67 * (15 + 53))) + ((14 * (63 * (76 + (((1 + 78) + ((14 * 41) + (8 + 67))) + ((50 * (53 * (((39 * 19) * 24) + 88))) + 15))))) * 97)) * * % java RandomExpression 0.25 * ((56 * 28) * (52 + 52)) * * % java Expr 0.3 * Exception in thread "main" java.lang.StackOverflowError * at java.lang.System.arraycopy(Native Method) * at java.lang.String.getChars(String.java:726) * ******************************************************************************/ public class RandomExpression { public static String generate(double p) { double r = StdRandom.uniformDouble(0.0, 1.0); if (r <= p) return "(" + generate(p) + " + " + generate(p) + ")"; else if (r <= 2*p) return "(" + generate(p) + " * " + generate(p) + ")"; else return "" + StdRandom.uniformInt(100); } public static void main(String[] args) { double p = Double.parseDouble(args[0]); StdOut.println(generate(p)); } }