Another update from ingydotnet^djgoku

Task/Longest-common-subsequence/JavaScript/longest-common-subsequence-5.js

@@ -0,0 +1,42 @@
+function lcs_greedy(x,y){
+  var p1, i, idx,
+      symbols = {},
+      r = 0,
+      p = 0,
+      l = 0,
+      m = x.length,
+      n = y.length,
+      s = new Buffer((m < n) ? n : m);
+
+  p1 = popsym(0);
+
+  for (i = 0; i < m; i++) {
+    p = (r === p) ? p1 : popsym(i);
+    p1 = popsym(i + 1);
+    if (p > p1) {
+      i += 1;
+      idx = p1;
+    } else {
+      idx = p;
+    }
+
+    if (idx === n) {
+      p = popsym(i);
+    } else {
+      r = idx;
+      s[l] = x.charCodeAt(i);
+      l += 1;
+    }
+  }
+  return s.toString('utf8', 0, l);
+	
+  function popsym(index) {
+    var s = x[index],
+        pos = symbols[s] + 1;
+
+    pos = y.indexOf(s, ((pos > r) ? pos : r));
+    if (pos === -1) { pos = n; }
+    symbols[s] = pos;
+    return pos;
+  }
+}