Program which calculates the sum of the first 10 Fibonacci numbers that are bigger than 1000

Question

I want to write a program that prints me only the first 10 Fibonacci numbers that > 1000.

I tried using head, n=10L but no success.

len <- 30
fibvals <- numeric(len)
fibvals[1] <- 1
fibvals[2] <- 1
for (i in 3:len) { 
  fibvals[i] <- fibvals[i-1]+fibvals[i-2]
} 
for (i in 1:length(fibvals)){
  if(fibvals[i] > 1000){print(head(fibvals[i],n=10L))}
}

I expect the first 10 fibvals to show, but it keeps showing me up to my len = 30 (so 4 extra)

`fibvals[i]` is a scalar so `head(fibvals[i],n=10L)` equals `fibvals[i]` . — G. Grothendieck, Jul 14 '19 at 11:51
Keep a count of how many you have printed so far and stop when you get to 10. — G. Grothendieck, Jul 14 '19 at 11:58
Several ways to solve this. `sum(fibvals[fibvals > 1000][1:10])`. Adding `if(fibvals[i] > 1000){fibSum <- fibSum + fibvals[i]; fibIterator <- fibIterator + 1; if(fibIterator = 1) break}` to the first loop after initiating the variable prior to the loop. (`fibIterator <- 0; fibSum <- 0`). Your solution works fine as well. `sum(head(fibval[fibval > 1000], 10))` would work as well. — Oliver, Jul 14 '19 at 18:30

score 0 · Answer 1 · answered Jul 14 '19 at 19:42

an other approach using a while-loop

#initialisation
m <- matrix( data = c(1,1), nrow = 2 )
n = 10
limit = 1000

#add new row to m,
# until m contains 10 (n) values above 1000 (limit)
while(length(m[ m > limit]) < n ){ 
  m <- rbind( m, m[length(m)] + m[length(m)-1] )
}
#print the values above the limit
print( m[m>limit] )

Program which calculates the sum of the first 10 Fibonacci numbers that are bigger than 1000

1 Answers1