题解 | #整型数组合并#
挑7
http://www.nowcoder.com/practice/ba241b85371c409ea01ac0aa1a8d957b
题解
挑7有两种情况:
- i%7==0 表示 i是7的倍数。
- String.valueOf(i).indexOf('7') != -1 说明字符串中包含7
代码
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 (i % 7 == 0 || String.valueOf(i).indexOf('7') != -1) {
count++;
}
}
System.out.println(count);
}
}
}