fix package name

medium/457/Solution.java

@@ -1,11 +0,0 @@
-class Solution {
-    public boolean circularArrayLoop(int[] nums) {
-        return false;
-    }
-
-    public static void main(String[] args) {
-        Solution s = new Solution();
-        int[] n1 = {1, 2, 3, 4};
-        System.out.println(s.circularArrayLoop(n1));
-    }
-}

medium/_457/Solution.java

@@ -0,0 +1,56 @@
+package _457;
+
+class Solution {
+    public boolean circularArrayLoop(int[] nums) {
+        int n = nums.length;
+        // Start from every element
+        for (int i = 0; i < n; i++) {
+            // Mark all visited points as 0 (after loop no found),
+            // continue to next loop if curr loop starts with 0
+            if (nums[i] == 0) {
+                continue;
+            }
+            int slow = i;
+            int fast = nextIndex(i, nums);
+            int fastNext = nextIndex(fast, nums); // The next element of fast
+            // Break if the direction of fast and fastNext do change
+            // or if the fast or fastNext reach 0
+            while (nums[fast] * nums[i] > 0 && nums[fastNext] * nums[i] > 0) {
+                slow = nextIndex(slow, nums);
+                fast = nextIndex(fastNext, nums);
+                fastNext = nextIndex(fast, nums);
+                // If fast catch up slow
+                if (slow == fast) {
+                    // Single element in loop
+                    if (fast == fastNext) {
+                        break;
+                    }
+                    return true;
+                }
+            }
+            // Set the path to 0
+            slow = i;
+            while (nums[slow] * nums[i] > 0) {
+                nums[slow] = 0;
+                slow = nextIndex(slow, nums);
+            }
+        }
+        return false;
+    }
+
+    public static void main(String[] args) {
+        Solution s = new Solution();
+        int[] n1 = { 2, -1, 1, 2, 2 };
+        System.out.println(s.circularArrayLoop(n1));
+        int[] n2 = { -1, 2 };
+        System.out.println(s.circularArrayLoop(n2));
+        int[] n3 = { -2, 1, -1, -2, -2 };
+        System.out.println(s.circularArrayLoop(n3));
+    }
+
+    private int nextIndex(int i, int[] nums) {
+        int n = nums.length;
+        int index = i + nums[i];
+        return index >= 0 ? index % n : n + (index % n);
+    }
+}

medium/_464/Solution.java

@@ -0,0 +1,38 @@
+package _464;
+
+class Solution {
+    // maxChoosableInteger will not be larger than 20,
+    // and desiredTotal will not be larger than 300
+    public boolean canIWin(int maxChoosableInteger, int desiredTotal) {
+        return canIWinIter(maxChoosableInteger, desiredTotal, 0, 0, true);
+    }
+
+    public static void main(String[] args) {
+        Solution s = new Solution();
+        System.out.println(s.canIWin(10, 11));
+        System.out.println(s.canIWin(10, 0));
+    }
+
+    private boolean canIWinIter(int maxChoosableInteger, int desiredTotal, int intChoosen, int total,
+            boolean isMyTurn) {
+        if (total >= desiredTotal) {
+            System.out.println(total);
+            if (isMyTurn) {
+                return true;
+            }
+            return false;
+        }
+        for (int i = 0; i < maxChoosableInteger; i++) {
+            boolean isChoosen = (intChoosen & (1 << i)) != 0;
+            if (isChoosen) {
+                continue;
+            }
+            boolean iCanWin = canIWinIter(maxChoosableInteger, desiredTotal, intChoosen | (1 << i), total + i + 1,
+                    !isMyTurn);
+            if (iCanWin) {
+                return true;
+            }
+        }
+        return false;
+    }
+}