'commit'

TangDou/Topic/Mobius/SQP4168.cpp

@@ -1,14 +1,14 @@
-#include <iostream>
-#include <cstdio>
-#include <cmath>
+#include <bits/stdc++.h>
 using namespace std;
 #define int long long
 #define endl "\n"
 
-const int N = 1e7 + 10; // 枚举到sqrt(1e14)=1e7即可
+const int M = 110, N = 10000010;
+
+int t, m, sqrtN, n, ans, q[M];
 
 // 筛法求莫比乌斯函数(枚举约数)
-int mu[N], s1[N], s2[N]; // s1[N]:梅滕斯函数,也就是莫比乌斯函数的前缀和
+int mu[N], sum[N]; // sum[N]:梅滕斯函数,也就是莫比乌斯函数的前缀和
 int primes[N], cnt;
 bool st[N];
 void get_mobius(int n) {
@@ -29,34 +29,30 @@ void get_mobius(int n) {
         }
     }
     // 维护u(x)前缀和:梅滕斯函数
-    for (int i = 1; i <= n; i++) s1[i] = s1[i - 1] + mu[i];
-    for (int i = 1; i <= n; i++) s2[i] = s2[i - 1] + mu[i] * mu[i];
-}
-
-int calc(int n) {
-    if (n <= N) return s2[n];
-    int res = 0, m = sqrt(n);
-    for (int l = 1, r; l <= m; l = r + 1) {
-        r = min((int)sqrt(n / (n / (l * l))), m);
-        res += (n / (l * l)) * (s1[r] - s1[l - 1]);
-    }
-    return res;
+    for (int i = 1; i <= n; i++) sum[i] = sum[i - 1] + mu[i];
 }
 
 signed main() {
 #ifndef ONLINE_JUDGE
     freopen("SQP4168.in", "r", stdin);
-    /*
-    1
-    608
-    60792710185947
-    */
 #endif
-    int n, T;
-    cin >> T;
-    get_mobius(N - 1);
-    while (T--) {
-        cin >> n;
-        cout << calc(n) << endl;
+    cin >> t;
+    for (int i = 1; i <= t; i++) {
+        cin >> q[i];
+        n = max(n, q[i]);
     }
-}
+    sqrtN = sqrt(n);
+
+    get_mobius(sqrtN); // 线性求莫比乌斯函数, 前缀和
+
+    for (int i = 1; i <= t; i++) {
+        n = q[i];
+        ans = 0;
+        for (int l = 1, r; l <= n; l = r + 1) {
+            if (n / (l * l) == 0) { break; }
+            r = sqrt(n / (n / (l * l)));
+            ans += n / (l * l) * (sum[r] - sum[l - 1]);
+        }
+        printf("%lld\n", ans);
+    }
+}