10/13

Author: surajr

java/.DS_Store

@@ -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));
+ }
+}

java/BuddyStrings.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;
+ }
+}

java/scoreOfParenthesis.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);
+ }
+}