4.9 BST Sequences: saving before trying a new approach

Author: amejiarosario

src/trees-and-graphs/bst-sequence.js

@@ -47,14 +47,31 @@ function weave(prefix = [], arrays1 = [[]], arrays2 = [[]]) {
       } else if(!array2.length) {
         result = result.concat(weave(prefix.concat(array1), [array2]));
       } else {
-        result = result.concat(weave(prefix.concat(array1), [array2]));
-        result = result.concat(weave(prefix.concat(array2), [array1]));
+        // weave the arrays
+        array2.forEach(function (_, i2) {
+          array1.forEach(function (_, i1) {
+            results.push( prefix.concat(array1.slice(i1), array2.slice(0, i2 + 1), array1.slice(), array2.slice()) );
+          });
+        });
+
+        // array1.forEach((_, i, array) => {
+        //   // if(array.slice(i+1).length == 1) { return; }
+        //   result = result.concat(weave(prefix.concat(array1.slice(0, i + 1)), [array1.slice(i + 1)], [array2]));
+        // });
+        //
+        // array2.forEach((_, i, array) => {
+        //   // if(array.slice(i+1).length == 1) { return; }
+        //   result = result.concat(weave(prefix.concat(array2.slice(0, i + 1)), [array1], [array2.slice(i + 1)]));
+        // });
+
+        // result = result.concat(weave(prefix.concat(array1), [array2]));
+        // result = result.concat(weave(prefix.concat(array2), [array1]));
       }
     });
   });
 
-  // console.log('\nweave (', prefix, arrays1, arrays2, ')');
-  // console.log('\t =>', result);
+  console.log('\nweave (', prefix, arrays1, arrays2, ')');
+  console.log('\t =>', result);
 
   return result;
 }

src/trees-and-graphs/bst-sequence.spec.js

@@ -23,6 +23,9 @@ describe('weave', function () {
     ]);
   });
 
+  /**
+   * weave(2, 1, 3) = weave([2,1], 3) + weave([2,3], 1)
+   */
   it('should weave given two arrays', function () {
     const prefix = 2;
     const arrays1 = [[1]];
@@ -35,7 +38,7 @@ describe('weave', function () {
   });
 
   /**
-   * weave(5, [3,2], [8]) = weave([5,3,2], [], [8]) + weave([5, 8], [3,2], [])
+   * weave(5, [3,2], [8]) = weave([5,3], [2], [8]) + weave([5, 8], [3,2], [])
    */
   it('should cross array 1 with array 2 keeping the same order', function () {
     const prefix = 5;
@@ -49,6 +52,41 @@ describe('weave', function () {
     expect(weave(prefix, arrays1, arrays2)).to.eql(weaved);
   });
 
+  /**
+   * weave([5,3,2], 1, 8) + weave([5,3,8])
+   */
+  it('should cross array 1 with array 2 keeping the same order', function () {
+    const prefix = 5;
+    const arrays1 = [[3, 2, 1]];
+    const arrays2 = [[8]];
+    const weaved = [
+      [5, 3, 2, 1, 8],
+      [5, 3, 2, 8, 1],
+      [5, 3, 8, 2, 1],
+      [5, 8, 3, 2, 1],
+    ];
+    expect(weave(prefix, arrays1, arrays2)).to.eql(weaved);
+  });
+
+  it('should cross array 1 with array 2 keeping the same order', function () {
+    const prefix = 5;
+    const arrays1 = [[3, 2, 1]];
+    const arrays2 = [[8, 9]];
+    const weaved = [
+      [5, 3, 2, 1, 8, 9],
+      [5, 3, 2, 8, 1, 9],
+      [5, 3, 2, 8, 9, 1],
+      [5, 3, 8, 2, 1, 9],
+      [5, 3, 8, 2, 9, 1],
+      [5, 3, 8, 9, 2, 1],
+      [5, 8, 3, 2, 1, 9],
+      [5, 8, 3, 2, 9, 1],
+      [5, 8, 3, 9, 2, 1],
+      [5, 8, 9, 3, 2, 1],
+    ];
+    expect(weave(prefix, arrays1, arrays2)).to.eql(weaved);
+  });
+
   it('should cross array 2 with array 1 keeping the same order', function () {
     const prefix = 5;
     const arrays1 = [[3]];