romantointeger.java

package strings;

public class romantointeger {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
//		roman("CCXLVII");
		roman("CMXVI");
//		roman("CCXL");

	}

	public static void roman(String str) {
		int sum = 0, oldvalue = Integer.MAX_VALUE, currvalue = 0;
		for (int i = 0; i < str.length(); i++) {
			if (str.charAt(i) == 'I') {
				currvalue = 1;
			} else if (str.charAt(i) == 'V') {
				currvalue = 5;
			} else if (str.charAt(i) == 'X') {
				currvalue = 10;
			} else if (str.charAt(i) == 'L') {
				currvalue = 50;
			} else if (str.charAt(i) == 'C') {
				currvalue = 100;
			} else if (str.charAt(i) == 'D') {
				currvalue = 500;
			} else if (str.charAt(i) == 'M') {
				currvalue = 1000;
			}
			if (currvalue <= oldvalue) {
				sum += currvalue;
			} else {
				sum = sum - (2 * oldvalue) + currvalue;
			}
			oldvalue = currvalue;
		}
		System.out.println(sum);
	}

}