P1980,java
时间: 2023-12-18 07:29:26 浏览: 22
题目P1980是一个简单的计数问题,要求计算在1到n的所有数字中,数字x出现的次数。以下是两种Java实现方法:
方法一:
```java
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
int n = sc.nextInt();
int x = sc.nextInt();
int g = 0;
for (int i = 1; i <= n; i++) {
String s = Integer.toString(i);
for (int j = 0; j < s.length(); j++) {
int a = s.charAt(j) - 48;
if (a == x) {
g++;
}
}
}
System.out.println(g);
}
}
```
方法二:
```java
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
int a = sc.nextInt();
int b = sc.nextInt();
int count = 0;
for (int i = 1; i <= a; i++) {
String[] str = (i + "").split("");
for (int j = 0; j < str.length; j++) {
if (str[j].equals(String.valueOf(b))) {
count++;
}
}
}
System.out.println(count);
}
}
```