View Compilation Error

0_0_16974726_3683\Main.java:1: 错误: 非法字符: '#'
#define PI 3.1415927 
^
0_0_16974726_3683\Main.java:1: 错误: 需要class, interface或enum
#define PI 3.1415927 
        ^
0_0_16974726_3683\Main.java:2: 错误: 非法字符: '#'
#include<stdio.h> 
^
0_0_16974726_3683\Main.java:6: 错误: 需要class, interface或enum
    while(scanf("%lf",&n)!=EOF) //用double时，需要用lf
    ^
0_0_16974726_3683\Main.java:9: 错误: 需要class, interface或enum
    } 
    ^
0_0_16974726_3683\Main.java:11: 错误: 需要class, interface或enum
}
^
6 个错误