题目描述:
输出7有关数字的个数,包括7的倍数,还有包含7的数字(如17,27,37...70,71,72,73...)的个数
Java实现:
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
while (sc.hasNext()) {
int n = sc.nextInt();
int count = 0;
for (int i = 1; i <= n; i++) {
if (beishu(i) || baohan(i))
count++;
}
System.out.println(count);
}
}
private static boolean beishu(int n) {
if (n % 7 == 0)
return true;
return false;
}
private static boolean baohan(int n) {
String strn = String.valueOf(n);
if (strn.contains("7"))
return true;
return false;
}
}
关键点:
- 因为n的范围较小并且只需要得到个数,因此用遍历的方法