Solution.java

public class Solution {
    public int romanToInt(String s) {
            int a;
    int b;
    int c;
    int d;
    String sa="";
    String sb="";
    String sc="";
    String sd="";
    String flag="ǧ";
    for (int i = 0; i < s.length(); i++) {
        String t=s.substring(i,i+1);
        if (flag.equals("ǧ")) {
            if(t.equals("M")){
                sa+=t;
                continue;
            }else {
                flag="°Ù";
            }
        }
        if (flag.equals("°Ù")) {
            if (t.equals("C")||t.equals("D")||t.equals("M")) {
                sb+=t;
                continue;
            }else {
                flag="Ê®";
            }
        }
        if (flag.equals("Ê®")) {
            if (t.equals("X")||t.equals("L")||t.equals("C")) {
                sc+=t;
                continue;
            }else {
                flag="¸ö";
            }
        }
        if (flag.equals("¸ö")) {
            if (t.equals("I")||t.equals("V")||t.equals("X")) {
                sd+=t;
                continue;
            }
        }
        
    }
    a=sa.length();
    if (sb.length()==0) {
        b=0;
    }else if (sb.contains("M")) {
        b=9;
    }else if(sb.substring(0,1).equals("D")){
        b=5+sb.length()-1;
    }else if (sb.contains("D")) {
        b=4;
    }else {
        b=sb.length();
    }
    if (sc.length()==0) {
        c=0;
    }else if (sc.contains("C")) {
        c=9;
    }else if(sc.substring(0,1).equals("L")){
        c=5+sc.length()-1;
    }else if (sc.contains("L")) {
        c=4;
    }else {
        c=sc.length();
    }
    if (sd.length()==0) {
        d=0;
    }else if (sd.contains("X")) {
        d=9;
    }else if(sd.substring(0,1).equals("V")){
        d=5+sd.length()-1;
    }else if (sd.contains("V")) {
        d=4;
    }else {
        d=sd.length();
    }
    return 1000*a+100*b+10*c+d;
    }
}