assigement.R

assignment = function(x, k = 4) {
	
	names(x) = seq_along(x)
	
	y = vector("list", k)
	ysum = sapply(y, function(x) 0)
 
	flag = 0
	while(length(x)) {
		if(flag) {
			a = sort(x, decreasing = FALSE)[1:ifelse(length(x) > k, k, length(x))]
			for(i in seq_along(a)) {
				o = order(ysum, decreasing = TRUE)
				y[[ o[i] ]] = c(y[[ o[i] ]], a[i])
			}
			x = x[ -order(x, decreasing = FALSE)[seq_along(a)] ]
			flag = !flag
		} else {
			a = sort(x, decreasing = TRUE)[1:ifelse(length(x) > k, k, length(x))]
			for(i in seq_along(a)) {
				o = order(ysum, decreasing = FALSE)
				y[[ o[i] ]] = c(y[[ o[i] ]], a[i])
			}
			x = x[ -order(x, decreasing = TRUE)[seq_along(a)] ]
			flag = !flag
		}
		
		ysum = sapply(y, sum)
	}
	lapply(y, function(x) sort(as.numeric(names(x))))
}

chr.length = c(
	chr1=249250621,
	chr2=243199373,
	chr3=198022430,
	chr4=191154276,
	chr5=180915260,
	chr6=171115067,
	chr7=159138663,
	chr8=146364022,
	chr9=141213431,
	chr10=135534747,
	chr11=135006516,
	chr12=133851895,
	chr13=115169878,
	chr14=107349540,
	chr15=102531392,
	chr16=90354753,
	chr17=81195210,
	chr18=78077248,
	chr19=59128983,
	chr20=63025520,
	chr21=48129895,
	chr22=51304566,
	chrX=155270560,
	chrY=59373566)

assignment(chr.length)
assignment(chr.length, 8)