Added Replace All Digits with Characters.java

Author: varunu28

Easy/Replace All Digits with Characters.java

@@ -0,0 +1,11 @@
+class Solution {
+  public String replaceDigits(String s) {
+    StringBuilder sb = new StringBuilder();
+    int n = s.length();
+    for (int i = 1; i < n; i += 2) {
+      char c = s.charAt(i - 1);
+      sb.append(c).append((char) (((int) c) + Character.getNumericValue(s.charAt(i))));
+    }
+    return n % 2 != 0 ? sb.append(s.charAt(n - 1)).toString() : sb.toString();
+  }
+}