add pancake sort

AdhityaRamadhanus · AdhityaRamadhanus · commit bfc8eefcabc2 · 2016-08-22T21:51:56.000+07:00
diff --git a/algorithm/category.json b/algorithm/category.json
@@ -85,7 +85,8 @@
          "quick": "Quicksort",
          "radix": "Radix Sort",
          "selection": "Selection Sort",
-         "shell": "Shellsort"
+         "shell": "Shellsort",
+         "pancake": "Pancake Sort"
       },
       "name": "Sorting"
    },
diff --git a/algorithm/sorting/pancake/basic/code.js b/algorithm/sorting/pancake/basic/code.js
@@ -0,0 +1,31 @@
+logger._print('original array = [' + D.join(', ') + ']');
+var N = D.length;
+function flip (start) {
+  tracer._select(start, N)._wait();
+  var idx = 0;
+  for (var i=start;i<(start+N)/2;i++) {
+    tracer._select(i)._wait();
+    var temp = D[i];
+    D[i] = D[N-idx-1];
+    D[N-idx-1] = temp;
+    idx++;
+    tracer._notify(i, D[i])._notify(N-idx, D[N-idx])._wait();
+    tracer._denotify(i)._denotify(N-idx);
+    tracer._deselect(i);
+  }
+  tracer._deselect(start, N);
+}
+for (var i=0;i<N-1;i++) {
+  logger._print('round ' + (i+1));
+  var currArr = D.slice(i, N);
+  var currMax = currArr.reduce((prev, curr, idx) => {
+    return (curr > prev.val) ? { idx: idx, val: curr} : prev;
+  }, {idx: 0, val: currArr[0]});
+  if (currMax.idx !== i) {
+    logger._print('flip at ' + (currMax.idx+i) + ' (step 1)');
+    flip(currMax.idx+i, N);
+    logger._print('flip at ' + (i) + ' (step 2)');
+    flip(i, N);
+  }
+}
+logger._print('sorted array = [' + D.join(', ') + ']');
diff --git a/algorithm/sorting/pancake/basic/data.js b/algorithm/sorting/pancake/basic/data.js
@@ -0,0 +1,5 @@
+var chart = new ChartTracer();
+var tracer = new Array1DTracer().attach(chart);
+var logger = new LogTracer();
+var D = Array1D.random(10);
+tracer._setData(D);
diff --git a/algorithm/sorting/pancake/desc.json b/algorithm/sorting/pancake/desc.json
@@ -0,0 +1,14 @@
+{
+  "Pancake Sort": "Pancake Sort,inspired from sorting a stack of pancake using spatula, is a simple sorting algorithm that only have 1 operation called flip. </br> flip (i) : Reverse array from i to N where N is length of array ",
+  "Complexity": {
+    "time": "worst $O(n^2)$",
+    "space": "worst $O(1)$ auxiliary"
+  },
+  "References": [
+    "<a href='https://en.wikipedia.org/wiki/Pancake_sorting'>Wikipedia</a>",
+    "<a href='http://www.geeksforgeeks.org/pancake-sorting/'>Geeksforgeeks</a>"
+  ],
+  "files": {
+    "basic": "Pancake sort"
+  }
+}
