feat: menambahkan koversi romawi ke integer

close #44

Signed-off-by: slowy07 <[email protected]>

Author: slowy07

Diff for: conversion/RomanToInteger.java

@@ -0,0 +1,51 @@
+import java.util.*;
+
+public class RomanToInteger{
+  private static Map<Character, Integer> map =
+    new HashMap<Character, Integer> (){
+      private static final long serialVersionUID = 87605733047260530L;
+      {
+        put('I', 1);
+        put('V', 5);
+        put('X', 10);
+        put('L', 50);
+        put('C', 100);
+        put('D', 500);
+        put('M', 1000);
+      }
+    };
+
+  /**
+   * fungsi yang akan merubah dari angka romawi ke Integer
+   * @param string dari angka romawi
+   * @return Integer
+   */
+
+  public static int RomanToInt(String A){
+    A = A.toUpperCase();
+    char prev = ' ';
+    int sum = 0;
+    int newPrev = 0;
+    for(int i = A.length() - 1; i >= 0; i--){
+      char c = A.charAt(i);
+      if (prev != ' '){
+        newPrev = map.get(prev) > newPrev ? map.get(prev) : newPrev;
+      }
+      int currentNum = map.get(c);
+
+      if (currentNum >= newPrev){
+        sum += currentNum;
+      }
+      else{
+        sum -= currentNum;
+      }
+      prev = c;
+    }
+    return sum;
+  }
+
+  public static void main(String[] args){
+    int sum = RomanToInt("MDCCIV");
+    System.out.println(sum);
+  }
+}