diff --git a/R/lab_3_submission.R b/R/lab_3_submission.R
index 8af145a27e53d641d3d527a0b96283a0516d6d2a..e5d604cd52b1d9f867951f1ff6fbf92eba09f521 100644
--- a/R/lab_3_submission.R
+++ b/R/lab_3_submission.R
@@ -1,6 +1,6 @@
 
 
-#' Euclidian algorithm to find the 
+#' Euclidean algorithm to find the 
 #' greatest common divisor of two numbers
 #' @title  euclidean algorithm
 #' @param x first number
@@ -31,18 +31,19 @@ euclidean <- function(x,y) {
 
 #' @description init the detail table
 #' @title  initial the detail frame 
-#' @param init_node the start node to find the shortest path
-#' @param graph the structure of the graph,
+#' @param init_node the start node to find the shortest path, input should be one scalar of the graph
+#' @param graph the structure of the graph, input should be data frame or matrix
 #' eg:wiki_graph <- data.frame(v1=c(1,1,1,2,2,2,3,3,3,3,4,4,4,5,5,6,6,6),
 #'            v2=c(2,3,6,1,3,4,1,2,4,6,2,3,5,4,6,1,3,5),
 #'             w=c(7,9,14,7,10,15,9,10,11,2,15,11,6,6,9,14,2,9))
 init_node_distance_list <- function (init_node, graph) {
   node_distance_list <- list(init_node = 0)
-  # first, get all unqiue nodes 
+  # first, get all unique nodes 
   all_nodes <- unique(append(graph[,'v1'],graph[,'v2']))
   if (!init_node %in% all_nodes) {
     stop('node is not in graph')
   }
+  #built list and data frame for later comparison
   detail_frame <- data.frame(matrix(ncol=length(all_nodes),nrow = 3))
   names(detail_frame) <- all_nodes
   row.names(detail_frame) <- c('is_best_node','node_distance','previous_node')
@@ -58,11 +59,11 @@ init_node_distance_list <- function (init_node, graph) {
 #' @description
 #' the update method for detail table to record the shortest path
 #' @title update the detail frame when traversing to a new node
-#' @param node the current the node when traversing all the nodes to find the best way
+#' @param node the current node when traversing all the nodes to find the best way
 #' @param init_node the start node in the algorithm
-#' @param checked_nodes the nodes that having found the shortest path
-#' @param unchecked_nodes the nodes that having not found the shortest path
-#' @param detail_frame to store the shorest path , if it is the best node and the related distance
+#' @param checked_nodes the nodes that having been tested to find the shortest path
+#' @param unchecked_nodes the nodes that having been tested to find the shortest path
+#' @param detail_frame to store the shortest path , if it is the best node and the related distance
 #' @param graph the graph indicates the relationship of different nodes
 
 update_detail_path <- function(node,init_node,detail_frame,graph,checked_nodes,unchecked_nodes) {