Precreation contest files

misc/mysterious/tgc.cpp

@@ -0,0 +1,37 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+int a[500000];
+
+int main() {
+  ios_base::sync_with_stdio(false);
+  cin.tie(NULL);
+  freopen("tgc.inp", "r", stdin);
+
+  int n;
+  cin >> n;
+  for (int i = 0; i < n; i++)
+    cin >> a[i];
+  sort(a, a + n);
+
+  int res = 0;
+  for (int i = 0; i < n - 1; i++) {
+    if (a[i] != a[i + 1])
+      continue;
+
+    int l = i, r = n - 1;
+    int mid;
+    while (l < r) {
+      mid = (l + r) / 2;
+
+      if (a[mid] < 2 * a[i]) {
+        l = mid + 1;
+      } else {
+        r = mid;
+      }
+    }
+    res += r - mid + l;
+  }
+  cout << res << "\n";
+}