Aug27: Sliding window problem [H]

use sliding windows, w/ time: O(NlogN), space: O(N)

daily/Aug27.cc

@@ -0,0 +1,44 @@
+#include <unordered_map>
+#include <vector>
+using namespace std;
+
+class Solution {
+ public:
+  /**
+   * @brief LC3134: Median of the uniqueness array [H]
+   * Sliding window. Time: O(NlogN), Space: O(N)
+   *
+   * @param nums
+   * @return int
+   */
+  int medianOfUniquenessArray(vector<int>& nums) {
+    int len = nums.size();
+    long long k = ((long long)len * (len + 1) / 2 + 1) / 2;
+
+    auto check = [&](int upper) {
+      long long cnt = 0;
+      int l = 0;
+      unordered_map<int, int> freq;
+      for (int r = 0; r < len; r++) {
+        freq[nums[r]]++;               // expand right
+        while (freq.size() > upper) {  // too many elements in window
+          int out = nums[l++];
+          if (--freq[out] == 0) {  // out left
+            freq.erase(out);
+          }
+        }
+        cnt += r - l + 1;  // right is r, r - l + 1
+        if (cnt >= k) {
+          return true;
+        }
+      }
+      return false;
+    };
+    int le = 0, ri = len;
+    while (le + 1 < ri) {
+      int mid = (le + ri) / 2;
+      (check(mid) ? ri : le) = mid;
+    }
+    return ri;
+  }
+};

format.sh

@@ -2,6 +2,8 @@
 
 PROJECT_DIR="./daily"
 
-find $PROJECT_DIR -name uthash -prune -o -name "*.cpp" -o -name "*.c" -o -name "*.h" | xargs clang-format -i
+# find $PROJECT_DIR -name uthash -prune -o -name "*.cpp" -o -name "*.c" -o -name "*.h" | xargs clang-format -i
+
+find $PROJECT_DIR -name uthash -prune -o \( -name "*.cpp" -o -name "*.c" -o -name "*.h" \) -print0 | xargs -0 clang-format -i
 
 git add --all