# Use paste function here to split string, so it fits into 80
# characters as linter rules require
link = paste("https://raw.githubusercontent.com/",
    "go95/big_data_intro/master/Abdulkadiroglou.csv",
    sep = "")

articles <- read.csv(url(link))

# assign 9th column of data frame to a vector
cit_num_vector <- articles[,9]

# filter out NA values
cit_num_vector <- cit_num_vector[!is.na(cit_num_vector)]

# sort the vector
cit_num_vector_sorted <- sort(cit_num_vector)

Np <- length(cit_num_vector_sorted)

# The resulting table will have Np rows and 2 columns
res_table <- matrix(0:0, nrow = Np, ncol = 2)

curr_val <- 0
c <- 1

# Cycing through cit_num_vector
for (i in 1:length(cit_num_vector_sorted)) {
    # If it is a next unique value in the vector
    if (curr_val != cit_num_vector_sorted[i]) {
        # assign the first row of c-th column
        res_table[c, 1] <- cit_num_vector_sorted[i]

        # Np in this case will be equal to Np - i + 1
        res_table[c, 2] <- Np - i + 1

        # Assign a new value to curr_val to check
        # next values for uniqueness
        curr_val <- cit_num_vector_sorted[i]

        # Add 1 to counter variable
        c <- c + 1
    }
}

# Cycling through res_table
for (i in 1:Np) {
    cit_num <- res_table[i, 1]
    count <- res_table[i, 2]
    if (cit_num > count) {
        break
    }
    res <- res_table[i, 1]
}

print(res)