Weekly Contest 100

Author: MaskRay

bitwise-ors-of-subarrays.cc

@@ -0,0 +1,23 @@
+// Bitwise ORs of Subarrays
+#define FOR(i, a, b) for (remove_cv<remove_reference<decltype(b)>::type>::type i = (a); i < (b); i++)
+#define REP(i, n) FOR(i, 0, n)
+
+class Solution {
+public:
+  int subarrayBitwiseORs(vector<int>& a) {
+    vector<int> b[30];
+    unordered_set<int> s;
+    int n = a.size();
+    REP(i, n) {
+      s.insert(a[i]);
+      REP(k, 30)
+        if (a[i]>>k & 1) {
+          for (int j: b[k])
+            s.insert(a[j] |= a[i]);
+          b[k].clear();
+        } else
+          b[k].push_back(i);
+    }
+    return s.size();
+  }
+};

increasing-order-search-tree.cc

@@ -0,0 +1,21 @@
+// Increasing Order Search Tree
+class Solution {
+  TreeNode** y;
+  void f(TreeNode* x) {
+    if (x) {
+      f(x->left);
+      x->left = nullptr;
+      *y = x;
+      y = &x->right;
+      f(x->right);
+    }
+  }
+public:
+  TreeNode* increasingBST(TreeNode* root) {
+    TreeNode* ret;
+    y = &ret;
+    f(root);
+    *y = nullptr;
+    return ret;
+  }
+};

monotonic-array.cc

@@ -0,0 +1,7 @@
+// Monotonic Array
+class Solution {
+public:
+  bool isMonotonic(vector<int>& A) {
+    return max(adjacent_find(A.begin(), A.end(), less<>()), adjacent_find(A.begin(), A.end(), greater<>())) == A.end();
+  }
+};

orderly-queue.cc

@@ -0,0 +1,14 @@
+// Orderly Queue
+class Solution {
+public:
+  string orderlyQueue(string S, int K) {
+    if (K > 1)
+      sort(S.begin(), S.end());
+    else {
+      string r = S;
+      for (auto _: S)
+        S = min(S, r = r.substr(1) + r[0]);
+    }
+    return S;
+  }
+};