如何确定从序列中删除子序列的所有可能方式？

function remove(arr,sub){
  var _arr = [];
  arr.forEach(function(v,i){ if (!sub.has(i)) _arr.push(arr[i]); });
  return _arr;
}

function f(arr,sub){
  var res = [],
      lcs = new Array(sub.length + 1),
      nodes = new Array(sub.length + 1);
     
  for (var i=0; i<sub.length+1;i++){
    nodes[i] = [];
    lcs[i] = [];
   
    for (var j=0; j<(i==0?arr.length+1:1); j++){
      // store lcs and node count on the left
      lcs[i][j] = [0,0];
    }
  }
 
  for (var i=1; i<sub.length+1;i++){ 
    for (var j=1; j<arr.length+1; j++){
      if (sub[i-1] == arr[j-1]){
        lcs[i][j] = [1 + lcs[i-1][j-1][0],lcs[i][j-1][1]];
       
        if (lcs[i][j][0] == i){
                  // [arr index, left node count above]
          nodes[i].push([j - 1,lcs[i-1][j-1][1]]);
       
          lcs[i][j][1] += 1;
        }
       
      } else {
        lcs[i][j] = [Math.max(lcs[i-1][j][0],lcs[i][j-1][0]),lcs[i][j-1][1]];
      }
    }
  }
   
  function enumerate(node,i,accum){
    if (i == 0){
      res.push(remove(arr,new Set(accum)));
      return;
    }
    
    for (var j=0; j<node[1]; j++){
      var _accum = accum.slice();
      _accum.push(nodes[i][j][0]);
      
      enumerate(nodes[i][j],i - 1,_accum);
    }
  }
  
  nodes[sub.length].forEach(function(v,i){ 
    enumerate(nodes[sub.length][i],sub.length - 1,[nodes[sub.length][i][0]]); 
  });

  return res;
}

console.log(JSON.stringify(f([1,2,1,3,1,4,4], [1,4,4])));
console.log(JSON.stringify(f([8,6,4,4], [6,4,8])));
console.log(JSON.stringify(f([1,1,2], [1])));
console.log(JSON.stringify(f(['a','g','b','a','b','c','c'], ['a','b','c'])));