18/07/31 12:09:36.10 AXaAgLMZ.net
attack <- function(x){ # TRUE if on attack
n=length(x)
for(i in 1:(n-1)){
for(j in 1:(n-i)){
if(x[i+j]==x[i]+j | x[i+j]==x[i]-j) return(TRUE)
}
}
return(FALSE)
}
N_Queen<-function(n){
perm=gtools::permutations(n,n)
ret=apply(perm,1,attack)
perm[which(ret==FALSE),]
}
N_Queen(8)