user2543622 - 2 months ago 9

R Question

I would like to solve the challenge. The language of my preference is R. I am not sure how to receive input. On hackerrank coding window it says that

"# Enter your code here. Read input from STDIN. Print output to STDOUT"

So far I am used to receiving input by using

v1 <- readline("Enter two integers: ")

How should i receive input on hackerrank? I tried to see solved examples but couldn't find any solved examples :(

update 1

Below code works in R. Only problem is number of steps and ball values are not provided from keyboard input. We have to update them manually on line 1 and line2. How could I get update below solution so that it works on hackerrank?

`steps=4`

ball_numbers=c(1,2,2,2)

d=as.data.frame(c(0,1))

for (i in (1:(length(ball_numbers)-1)))

{

assign(x = paste("A", i, sep = ""),value = c(0,1))

e <- as.data.frame(get(paste("A", i, sep = "")))

colnames(e) <- paste("A", i, sep="")

d <- merge(d,e)

}

d=as.matrix(t(d))

answer=sum(ball_numbers %*% d)/ncol(d)

Below code produces correct answer

`# Enter your code here. Read input from STDIN. Print output to STDOUT`

nums <- read.table("/dev/stdin", sep=" ");

nums <- as.matrix(as.data.frame(t(nums)))

steps=nums[1]

ball_numbers=nums[2:length(nums)]

d=as.data.frame(c(0,1))

for (i in (1:(length(ball_numbers)-1)))

{

assign(paste("A", i, sep = ""),value = c(0,1))

e <- as.data.frame(get(paste("A", i, sep = "")))

colnames(e) <- paste("A", i, sep="")

d <- merge(d,e)

}

d=as.matrix(t(d))

#answer=as.numeric(format(round(sum(ball_numbers %*% d)/ncol(d),1),nsmall=1))

answer = print(format(sum(ball_numbers %*% d)/ncol(d),nsmall=1, digits = 1), quote = F)

write.table(as.numeric(answer), sep = "", append=T, row.names = F, col.names = F,quote = FALSE,)

I get below output

`[1] 2.0`

2

which is different from expected output which is below. How can i modify my code to get the correct format of output

`2.0`

Answer

Look at the "warmup".

```
data <- suppressWarnings(read.table("stdin", sep=" "));
```

Alternatively you can use

```
data <- suppressWarnings(readLines(file("stdin")))
```

Source (Stackoverflow)

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