ACM

ACM/CQUPT-19/B.cpp

@@ -0,0 +1,28 @@
+#include <iostream>
+using namespace std;
+long long xors(long long n) {
+    const long long X = 1000000007;
+    if (n * n < X) {
+        return n % 2;
+    }
+    long long result = 0;
+    long long j = 1;
+    while (j <= n) {
+        long long val = X / j;
+        long long left = j;
+        long long right = min(n, X / val);
+        long long count = right - left + 1;
+        result ^= count;
+        j = right + 1;
+    }
+    return result;
+}
+int main() {
+    int t;
+    cin >> t;
+    while (t-- > 0) {
+        long long n;
+        cin >> n;
+        cout << xors(n) << endl;
+    }
+}