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Algorithm to efficiently find all ultimate partents
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# assume tbl is original table | |
ult_parent <- rep(NA_integer_, nrow(tbl)) | |
get_parent_id <- function(tbl, id) { | |
# depends on your implementation | |
} | |
is_ult_parent <- function(tbl, id) { | |
# depends on your implementation | |
} | |
get_next_na <- function(ult_parent) { | |
idx <- is.na(ult_parent) | |
if (!any(idx)) return NULL | |
seq_along(ult_parent)[idx][1] | |
} | |
# seed ult_parent with records that are ult parents | |
# could be vectorized depending what the actual condition is | |
for (id in seq_along(ult_parent)) { | |
if (is_ult_parent(tbl, id)) { | |
ult_parent[id] <- id | |
} | |
} | |
while(!is.null(get_next_na(ult_parent))) { | |
id <- get_next_na(ult_parent) | |
parent_group <- id | |
while(is.na(ult_parent[id])) { | |
parent_group <- append(parent_group, id) | |
id <- get_parent_id(tbl, id) | |
} | |
ult_parent[parent_group] <- parent_id | |
} |
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after running algorithm, ult_parent will be a map from id to ultimate parent_id