In [1]:

    

library(foreach)


    

In [2]:

    

data <- read.csv("data.csv",header=F)
data


    

    






V1
V2
V3
V4
V5
V6
V7
V8
V9
V10
...
V140
V141
V142
V143
V144
V145
V146
V147
V148
V149

	
1
R5 
 L2
 L1
 R1
 R3
 R3
 L3
 R3
 R4
 L2
...
 R1
 R2
 R2
 R2
 L1
 L1
 L2
 L5
 L3
 L1

In [3]:

    

# Small trim function because there is trailling and leading spaces in the data file
trim <- function (x) gsub("^\\s+|\\s+$", "", x)


    

In [4]:

    

curX <-0
curY <-0
face <-0
locations <- matrix(c(0,0), ncol =2)

a <- foreach(x=data) %do% {
    face <- if((substr(trim(x),1,1) == "R")) face+1 else face-1;
    lValue <- strtoi(substr(trim(x),2,nchar(trim(x))));
    
    #SubLoop to add all steps into the location matrix
    b <- foreach(y=1:lValue) %do%{
        switch(face%%4+1, {curX <- curX+1}, {curY <- curY+1}, {curX <- curX-1}, {curY <- curY-1});
        locations <- rbind(locations, c(curX,curY))
    } 
}

HQ <- subset(locations,duplicated(locations))[1,] #Get the first


    

In [5]:

    

paste("Q1 -- Shortest path to destination is", (abs(curX) + abs(curY)),"blocks away!")
paste("Q2 -- Shortest path to HQ is", (abs(HQ[1]) + abs(HQ[2])),"blocks away!")


    

    





"Q1 -- Shortest path to destination is 287 blocks away!"






    





"Q2 -- Shortest path to HQ is 133 blocks away!"