June 2018 Update

Task/Non-decimal-radices-Convert/R/non-decimal-radices-convert.r

@@ -0,0 +1,26 @@
+int2str <- function(x, b) {
+	if(x==0) return("0")
+	if(x<0) return(paste0("-", base(-x,b)))
+	
+	map <- c(as.character(0:9), letters)
+	res <- ""
+	while (x>0) {
+		res <- c(map[x %% b + 1], res)
+		x <- x %/% b
+	}
+	return(paste(res, collapse=""))
+}
+
+str2int <- function(s, b) {
+	map <- c(as.character(0:9), letters)
+	s <- strsplit(s,"")[[1]]
+	res <- sapply(s, function(x) which(map==x))
+	res <- as.vector((res-1) %*% b^((length(res)-1):0))
+	return(res)
+}
+
+## example: convert 255 to hex (ff):
+int2str(255, 16)
+
+## example: convert "1a" in base 16 to integer (26):
+str2int("1a", 16)