题解 | #判断各类型字符个数#

public static void method(int start, int end) {
    int count=0;
    //write your code here......
    if(start>end){
        int temp=start;
        start=end;
        end=temp;
    }
    for (int i=(start<3)?3:start;i<=end;i++ ){
		boolean flag = true;//重置flag
		for (int j=2;j<=Math.sqrt(i);j++ ){//优化二：缩小范围
			if (i%j==0){
				flag = false;
				break;//优化一：只对非质数有效
			}
		}
		if (flag == true){
			count++;
		}
	}
    System.out.println(start+"到"+end+"之间有"+count+"个大于2的素数");
}

}