Five Nation Game

> library(plyr)
> x <- as.data.frame(matrix(data = NA, nrow = 10, ncol = 2))
> games <- c("AB", "AC", "AD", "AE", "BC", "BD", "BE", "CD", "CE",
+     "DE")
> x[, 2] <- games
> FiveNationResult <- function() {
+     res <- sample(c("10", "01"), 10, replace = T)
+     x[, 1] <- res
+     y <- as.data.frame(cbind(c(substr(x$V1, 1, 1), substr(x$V1,
+         2, 2)), c(substr(x$V2, 1, 1), substr(x$V2, 2, 2))))
+     y$score <- as.numeric(y[, 1]) - 1
+     colnames(y) <- c("code", "player", "score")
+     score_count <- ddply(y, .(player), summarise, score_count = sum(score))$score_count
+     result <- identical(score_count, rep(2, 5))
+     return(result)
+ }
> N <- 5000
> set.seed(2011)
> counter <- numeric(N)
> for (i in 1:N) {
+     result <- FiveNationResult()
+     counter[i] <- result
+ }
> print(sum(counter)/N)
[1] 0.0232