upload

Author: whd

274 H-Index .cpp

@@ -0,0 +1,19 @@
+class Solution {
+public:
+    int hIndex(vector<int>& citations) {
+        sort(begin(citations), end(citations));
+        int l = 0, r = citations.size();
+        auto ck = [&] (int x) {
+            return end(citations) - lower_bound(begin(citations), end(citations), x) >= x;
+        };
+        while (l <= r) {
+            int mid = l + r >> 1;
+            if (ck(mid)) {
+                l = mid + 1;
+            } else {
+                r = mid - 1;
+            }
+        }
+        return r;
+    }
+};