[vpr][route] fix comment

Author: amin1377

vpr/src/route/router_lookahead_map.h

@@ -44,8 +44,8 @@ class MapLookahead : public RouterLookahead {
 /* provides delay/congestion estimates to travel specified distances
  * in the x/y direction */
 // This is a 6D array storing the cost to travel from a node of type CHANX/CHANY to a point that is dx, dy further, and is on the "layer_num" layer.
-// To store this information, the first index is the layer number that the node under consideration is on, the second index represents the type of channel (X/Y)
-// that the node under consideration belongs to, the third is the segment type (specified in the architecture file under the "segmentlist" tag), the fourth is the
+// To store this information, the first index is the layer number that the node under consideration is on, the second index is the layer number of the target node, the third index represents the type of channel (X/Y)
+// that the node under consideration belongs to, the forth is the segment type (specified in the architecture file under the "segmentlist" tag), the fourth is the
 // target "layer_num" mentioned above, the fifth is dx, and the last one is dy.
 typedef vtr::NdMatrix<util::Cost_Entry, 6> t_wire_cost_map; //[0..num_layers][0..num_layers][0..1][[0..num_seg_types-1][0..device_ctx.grid.width()-1][0..device_ctx.grid.height()-1]
                                                             //[0..1] entry distinguish between CHANX/CHANY start nodes respectively