1 files changed, 48 insertions, 0 deletions
diff --git a/entries/perryliao/fib.groovy b/entries/perryliao/fib.groovy
new file mode 100644
index 0000000..af1c4df
--- /dev/null
+++ b/entries/perryliao/fib.groovy
@@ -0,0 +1,48 @@
+pipeline {
+    agent any
+
+    parameters {
+        string defaultValue: '2', description: 'Number to compute in the Fibonacci Sequence', name: 'num', trim: true
+    }
+
+    stages {
+        stage('Create Cache') {
+            steps {
+                script {
+                    if (!fileExists("fibbonacciCache")) {
+                        sh 'echo "0\n1" > fibbonacciCache'
+                    }
+                }
+            }
+        }
+        stage('Validate Parameter') {
+            steps {
+                script {
+                    assert params.num.isInteger()
+                }
+            }
+        }
+        stage('Get Fibbonacci') {
+            steps {
+                script {
+                    result = fib(params.num.toInteger())
+                    println("The result is F(${params.num}) = ${result}")
+                }
+            }
+        }
+    }
+}
+
+int fib(int n, cache = 'fibbonacciCache') {
+    nComputed = sh(returnStdout: true, script: "wc -l < ${cache}").trim().toInteger()
+    if (n >= nComputed) {
+        // Need to do more recursion
+        result = fib(n - 2, cache) + fib(n - 1, cache)
+        sh "echo '${result}' >> ${cache}"
+        return result
+    } else {
+        // Already have what we need, so read from cache
+        return sh(returnStdout: true, script: "sed -n '${n + 1}p' ${cache}").trim().toInteger()
+    }
+}
+