Create 19E-C.cpp

Author: tmwilliamlin168

GoogleKickStart/19E-C.cpp

@@ -0,0 +1,54 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+int t, l, r;
+vector<int> v;
+
+int s(int r) {
+	return upper_bound(v.begin(), v.end(), r)-v.begin();
+}
+
+int solve() {
+	cin >> l >> r;
+	return (l<=1)+(l<=8&&8<=r)+(l<=4&&4<=r)+s(r)-s(l-1)+s(r/4)-s((l+3)/4-1)+r/2-(l-1)/2-r/4+(l-1)/4;
+}
+
+struct segmentedsieve {
+	void ac(int n, auto f) {
+		int s=1;
+		while(s*s<n)
+			++s;
+		vector<int> c(s+1), v;
+		for(int i=2; i<=s; ++i) {
+			if(c[i])
+				continue;
+			f(i);
+			v.push_back(i);
+			for(int j=i*i; j<=s; j+=i)
+				c[j]=1;
+		}
+		for(int i1=s+1, i2=2*s; i1<=n; i1+=s, i2+=s) {
+			c=vector<int>(s);
+			for(int p : v)
+				for(int j=(i1+p-1)/p; j*p<=i2; ++j)
+					c[j*p-i1]=1;
+			for(int j=i1; j<=i2; ++j)
+				if(!c[j-i1]&&j<=n)
+					f(j);
+		}
+	}
+} ss;
+
+int main() {
+	ios::sync_with_stdio(0);
+	cin.tie(0);
+
+	ss.ac(1e9, [](const int &i) {
+		v.push_back(i);
+	});
+	v.erase(v.begin());
+
+	cin >> t;
+	for(int i=1; i<=t; ++i)
+		cout << "Case #" << i << ": " << solve() << "\n";
+}