View Compilation Error

0_0_35523415_24722\Main.java:1: 错误: 非法字符: '#'
#include<iostream>
^
0_0_35523415_24722\Main.java:1: 错误: 需要class, interface或enum
#include<iostream>
        ^
0_0_35523415_24722\Main.java:2: 错误: 非法字符: '#'
#include<algorithm>
^
0_0_35523415_24722\Main.java:3: 错误: 非法字符: '#'
#include<stdio.h>
^
0_0_35523415_24722\Main.java:4: 错误: 非法字符: '#'
#include<math.h>
^
0_0_35523415_24722\Main.java:6: 错误: 非法字符: '#'
#define PI 3.1415927
^
0_0_35523415_24722\Main.java:6: 错误: 需要class, interface或enum
#define PI 3.1415927
        ^
0_0_35523415_24722\Main.java:8: 错误: 需要class, interface或enum
int main()
^
0_0_35523415_24722\Main.java:13: 错误: 需要class, interface或enum
	}
	^
9 个错误