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#
# See ../README.md
#
#
# Run as: Rscript ch-1.r < input-file
#
SUNDAY <- 0
MONDAY <- 1
TUESDAY <- 2
WEDNESDAY <- 3
THURSDAY <- 4
FRIDAY <- 5
SATURDAY <- 6
lookup <- array (c (261, 262,
260, 261,
260, 260,
261, 261,
261, 262,
261, 262,
261, 262), dim = c (2, 7))
anchors <- c (TUESDAY, SUNDAY, FRIDAY, WEDNESDAY)
doomsday <- function (year) {
anchor <- anchors [[1 + ((year %/% 100) %% 4)]]
y <- year %% 100
dday <- ((((y %/% 12) + (y %% 12) + ((y %% 12) %/% 4)) + anchor) %% 7)
return (dday)
}
is_leap <- function (year) {
if ((year %% 400 == 0) | (year %% 4 == 0) & (year %% 100 != 0)) {
return (1)
}
return (0)
}
stdin <- file ('stdin', 'r')
repeat {
year <- readLines (stdin, n = 1)
if (length (year) == 0) {
break
}
year = as.integer (year)
cat (lookup [[1 + is_leap (year), 1 + doomsday (year)]], "\n")
}
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