Read a roman number and convert that into decimal. For such a problem we have to find a suitable solution. we need to write a method to read the Roman number and a converter. there is a common patterns in Roman numbers and find a solution to convert.

For example , " III "means 1+1+1=3 , " V " means 5 " IV " means 4 how ?

let see , First read string and check from back to front .so now we have first " V " and " I " .now check last character is grater other one then " - " operator else " + "operator ( if V > I then 5 - 1 = 4 )