Improve array shrinking

1 files changed, 11 insertions, 3 deletions

diff --git a/pbt/ts/src/index.ts b/pbt/ts/src/index.ts
index 474b656..cf8b7ff 100644
--- a/pbt/ts/src/index.ts
+++ b/pbt/ts/src/index.ts
@@ -41,11 +41,19 @@ function reverse_is_self_inverse(arr: number[]): boolean {
 
 function shrinklist<A>(arr: A[]): A[][] {
   let result = [];
-  for (let i = 0; i < arr.length; i++) {
+
+  let tail = arr.slice(1);
+  let keep1 = arr.slice();
+  keep1.splice(1, 1);
+  result.push(tail,keep1);
+
+  if (arr.length >3) {
+    let half = Math.floor(arr.length / 2);
     let copy = arr.slice();
-    copy.splice(i, 1);
-    result.push(copy);
+    let secondHalf = copy.slice(half);
+    result.push(secondHalf);
   }
+
   return result;
 }