Create Solution3.cpp

Author: yanglbme

solution/0900-0999/0973.K Closest Points to Origin/Solution3.cpp

@@ -0,0 +1,33 @@
+class Solution {
+public:
+    vector<vector<int>> kClosest(vector<vector<int>>& points, int k) {
+        int n = points.size();
+        int dist[n];
+        int r = 0;
+        for (int i = 0; i < n; ++i) {
+            int x = points[i][0], y = points[i][1];
+            dist[i] = x * x + y * y;
+            r = max(r, dist[i]);
+        }
+        int l = 0;
+        while (l < r) {
+            int mid = (l + r) >> 1;
+            int cnt = 0;
+            for (int d : dist) {
+                cnt += d <= mid;
+            }
+            if (cnt >= k) {
+                r = mid;
+            } else {
+                l = mid + 1;
+            }
+        }
+        vector<vector<int>> ans;
+        for (int i = 0; i < n; ++i) {
+            if (dist[i] <= l) {
+                ans.emplace_back(points[i]);
+            }
+        }
+        return ans;
+    }
+};