Write a recursive function as follows (meta code of course) str_reverse(str){ if(isempty(str)) return str; else if(length(str) = even) then split str into str_1 and str_2; (of equal length) return str_reverse(str_2)+str_reverse(str_1); else split str into str_1, str_2, str_3; //if str is odd length, e.g. len = 7, split by 1-3 | 4 | 5-7 return str_reverse(str_3)+str_2+str_reverse(str_1); }