10/13

surajr · surajr · commit e7b2993a5390 · 2018-10-13T19:09:46.000-05:00
diff --git a/java/.DS_Store b/java/.DS_Store
diff --git a/java/BuddyStrings.java b/java/BuddyStrings.java
@@ -0,0 +1,20 @@
+class Solution {
+    public boolean buddyStrings(String A, String B) {
+        if(A.length() != B.length()) return false;
+                
+        if(A.equals(B)){
+            Set<Character> set = new HashSet<>();
+            for(char c:A.toCharArray()) set.add(c);
+            return set.size() < A.length();
+        }
+        
+        List<Integer> diff = new ArrayList<>();
+        for(int i=0; i<A.length(); i++)
+            if(A.charAt(i) != B.charAt(i))
+                diff.add(i);
+        
+        return diff.size()<=2 && 
+            A.charAt(diff.get(0)) == B.charAt(diff.get(1)) && 
+            A.charAt(diff.get(1)) == B.charAt(diff.get(0));
+    }
+}
diff --git a/java/scoreOfParenthesis.java b/java/scoreOfParenthesis.java
@@ -0,0 +1,20 @@
+class Solution {
+    public int scoreOfParentheses(String S) {
+        Stack<Integer> stack = new Stack<>();
+        for(char c:S.toCharArray()){
+            if(c == '(')
+                stack.push(-1);
+            else{
+                int cur = 0;
+                while(stack.peek() != -1)
+                    cur += stack.pop();
+                stack.pop();
+                stack.push(cur ==0 ? 1:2*cur);
+            }
+        }
+        int sum = 0;
+        while(!stack.isEmpty())
+            sum += stack.pop();
+        return sum;
+    }
+}
diff --git a/java/shiftingLetters.java b/java/shiftingLetters.java
@@ -0,0 +1,12 @@
+class Solution {
+    public String shiftingLetters(String S, int[] shifts) {
+        if(shifts.length == 0) return S;
+        char [] arr = S.toCharArray();
+        int shift = 0;
+        for(int i=shifts.length-1; i>=0; i--){
+            shift = (shift + shifts[i])%26;
+            arr[i] = (char)((arr[i] - 'a' + shift) % 26 + 'a');
+        }
+        return new String(arr);
+    }
+}
