Merge pull request #77 from JSLSasiRekha/practice

13. Roman to Integer

Author: PawanJaiswal08

RomanToInteger

@@ -0,0 +1,42 @@
+//       https://leetcode.com/problems/roman-to-integer/
+class Solution {
+    public int symbol_value(char A)
+    {
+        if(A=='I')
+            return 1;
+        else if(A=='V')
+            return 5;
+        else if(A=='X')
+            return 10;
+        else if(A=='L')
+            return 50;
+        else if(A=='C')
+            return 100;
+        else if(A=='D')
+            return 500;
+        else if(A=='M')
+            return 1000;
+        
+        
+        
+       return 0;  
+    }
+    public int romanToInt(String s) {
+        int sum=0,pre_value=0;
+        for(int i=0;i<s.length();i++)
+        {
+            int p=symbol_value(s.charAt(i));
+             sum+=p;
+            if(pre_value==1 && (p==5|| p==10))
+                sum-=2;
+            else if(pre_value==10 && (p==50|| p==100))
+                sum-=20;
+            else if(pre_value==100 && (p==500|| p==1000))
+                sum-=200;
+              pre_value=p; 
+            
+        }
+        
+        return sum;
+    }
+}