import java.io.*;
public class Sum {
public static int sum(int n) {
if (n < 1)
return 0;
else
return sum(n - 1) + n;
}
public static void main(String args[]) {
int result = 0;
String str;
int num = 0;
System.out.println("Please input the number:");
try {
DataInputStream in = new DataInputStream(System.in);
str = in.readLine(); // è¾å
¥çæ°åå符串
num = Integer.parseInt(str); // å符串转æ¢ææ´æ°å¼
} catch (Exception e) {
}
result = sum(num);// è°ç¨sumï¼ï¼ï¼æ±1+2+3+····+numï¼è¿ä¸ªresult好åè¦å°å
System.out.println(result); // æè¡è¾åºç»æ
}
}
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