Added solution of Roman_To_Integer (Leetcode) in Java.

Author: rajeshkumar2024

Hashing/Roman_to_Integer.java

@@ -0,0 +1,33 @@
+class Solution {
+    public int romanToInt(String s) {
+        Map<String,Integer> map = new HashMap<String,Integer>();
+        map.put("I",1);
+        map.put("V",5);
+        map.put("X",10);
+        map.put("L",50);
+        map.put("C",100);
+        map.put("D",500);
+        map.put("M",1000);
+        int sum = 0;
+        for (int i = 0 ; i < s.length()-1; i++){
+            int temp = map.get(s.substring(i,i+1));
+            int next = map.get(s.substring(i+1,i+2));
+            if (temp < next){
+                sum += (next-temp);
+            }
+            else{
+                sum += temp;
+            }
+        }
+        sum += map.get(s.substring(s.length()-1));
+        return sum;
+    }
+}
+
+// Example Test cases
+// Input: s = "IV"
+// Output: 4
+//
+//
+// Input: s = "IX"
+// Output: 9