更新了许多

判断素数.cpp

@@ -0,0 +1,14 @@
+#include <iostream>
+using namespace std;
+int main(){
+	int a,b=0;
+	cin >>a;
+	for(int i=2;i*i<=a;i++){
+		if(a%i==0){
+			cout <<a<<" is a prime number.";
+			return 0;
+		} 
+	}
+		cout <<a<<" is not a prime number.";
+	return 0;
+}