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fibonacci numbers
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| # python version | |
| known = {0:0, 1:1} | |
| def fibonacci(n): | |
| if n in known: | |
| return known[n] | |
| res = fibonacci(n-1) + fibonacci(n-2) | |
| known[n] = res | |
| return res | |
| fibonacci(9) | |
| fibonacci(10) | |
| fibonacci(20) | |
| fibonacci(300) | |
| # =============================================== | |
| # R version | |
| known = c(0, 1) | |
| names(known) = c("s0", "s1") | |
| fibonacci = function(n){ | |
| if(paste0("s", n) %in% names(known)) {known[paste0("s", n)]} else { | |
| res = fibonacci(n-1) + fibonacci(n-2) | |
| known[paste0("s", n)] <<- res | |
| unname(res)} | |
| } | |
| fibonacci(9) | |
| fibonacci(10) | |
| fibonacci(20) | |
| fibonacci(300) |
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