'commit'

C++专题课程/质数相关/三种方法.cpp

@@ -0,0 +1,52 @@
+#include<bits/stdc++.h>
+using namespace std;
+
+//<2F><><EFBFBD>淨
+bool isPrime(int n) {
+	if (n <= 3) {
+		return n > 1;
+	}
+	for(int i = 2; i < n; i++) {
+		if (n % i == 0) {
+			return false;
+		}
+	}
+	return true;
+}
+// ƽ<><C6BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ż<EFBFBD>
+bool isPrimeSqrt(int n) {
+	if (n <= 3) {
+		return n > 1;
+	}
+	int s = sqrt(n);
+	for (int i = 2; i <= s; i++) {
+		if(n % i == 0) {
+			return false;
+		}
+	}
+	return true;
+}
+//6x<36>Ż<EFBFBD><C5BB><EFBFBD>
+bool isPrime6x(int n) {
+	if (n <= 3) {
+		return n > 1;
+	}
+	if (n % 6 != 1 && n % 6 != 5) {
+		return false;
+	}
+	int s= sqrt(n);
+	for (int i = 5; i <= s; i += 6) {
+		if (n % i == 0 || n % (i + 2) == 0) {
+			return false;
+		}
+	}
+	return true;
+}
+
+int main() {
+	cout<<isPrime(131)<<endl;
+	cout<<isPrimeSqrt(131)<<endl;
+	cout<<isPrime6x(131)<<endl;
+
+	return 0;
+}