2702. problem b

https://www.acwing.com/problem/content/submission/code_detail/8055728/

AcWing/2702/2702.cpp

@@ -0,0 +1,50 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+int n, a, b, c, d, k, p;
+int mu[50005], primes[50005], sum[50005];
+bool vis[50005];
+
+void getMobius(int n) {
+    mu[1] = 1;
+    for (int i = 2; i <= n; i++) {
+        if (!vis[i]) {
+            primes[++p] = i;
+            mu[i] = -1;
+        }
+        for (int j = 1; i * primes[j] <= n; j++) {
+            vis[i * primes[j]] = true;
+            if (i % primes[j] == 0) break;
+            mu[i * primes[j]] = -mu[i];
+        }
+    }
+}
+
+int g(int k, int x) {
+    return k / (k / x);
+}
+
+long long f(int a, int b, int k) {
+    a = a / k, b = b / k;
+    long long res = 0;
+    int n = min(a, b);
+    for (int l = 1, r; l <= n; l = r + 1) {
+        r = min(n, min(g(a, l), g(b, l)));
+        res += (long long)(sum[r] - sum[l - 1]) * (a / l) * (b / l);
+    }
+    return res;
+}
+
+int main() {
+    cin >> n;
+    getMobius(50000);
+    for (int i = 1; i <= 50000; i++) {
+        sum[i] = sum[i - 1] + mu[i];
+    }
+    while (n--) {
+        cin >> a >> b >> c >> d >> k;
+        cout << f(b, d, k) - f(a - 1, d, k) - f(b, c - 1, k) + f(a - 1, c - 1, k) << endl;
+    }
+    return 0;
+}