Weekly Contest 110

Author: MaskRay

distinct-subsequences-ii.cc

@@ -0,0 +1,13 @@
+// Distinct Subsequences II
+class Solution {
+public:
+  int distinctSubseqII(string a) {
+    int mod = 1000000007, n = a.size(), s = 1;
+    vector<int> bs(26, -1);
+    for (int i = 0; i < n; i++) {
+      int &b = bs[a[i]-'a'];
+      b = exchange(s, (s*2L-(~b?b:0)+mod) % mod);
+    }
+    return s-1;
+  }
+};

minimum-area-rectangle.cc

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+// Minimum Area Rectangle
+class Solution {
+public:
+  int minAreaRect(vector<vector<int>> &points) {
+    unordered_set<int> s;
+    int mx = 40001*40001, r = mx;
+    for (auto &ps : points)
+      s.insert(ps[0]*40001+ps[1]);
+    for (auto &ps : points) {
+      int x0 = ps[0], y0 = ps[1];
+      for (auto &qs : points) {
+        int x1 = qs[0], y1 = qs[1];
+        if (x0 != x1 && y0 != y1) {
+          if (s.count(x0*40001+y1) && s.count(x1*40001+y0))
+            r = min(r, abs(x0-x1)*abs(y0-y1));
+        }
+      }
+    }
+    return r == mx ? 0 : r;
+  }
+};

range-sum-of-bst.cc

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+// Range Sum of BST
+class Solution {
+public:
+  int rangeSumBST(TreeNode *root, int L, int R) {
+    if (!root) return 0;
+    int v = root->val;
+    return (L<=v&&v<=R?v:0) + rangeSumBST(root->left, L, R) + rangeSumBST(root->right, L, R);
+  }
+};

reorder-log-files.cc

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+// Reorder Log Files
+class Solution {
+public:
+  vector<string> reorderLogFiles(vector<string> &logs) {
+    int n = logs.size();
+    vector<array<string, 3>> a;
+    for (auto &log : logs) {
+      int t = log.find(' ');
+      a.push_back({log.substr(t+1), log.substr(0, t), log});
+    }
+    stable_sort(a.begin(), a.end(), [&](auto &l, auto &r) {
+      int dl = l[0][0] <= '9', dr = r[0][0] <= '9';
+      if (dl != dr) return dl < dr;
+      if (dl) return false;
+      return l[0] != r[0] ? l[0] < r[0] : l[1] < r[1];
+    });
+    vector<string> r;
+    for (auto &x: a)
+      r.push_back(x[2]);
+    return r;
+  }
+};