View Compilation Error

0_0_16612106_26782.cpp:1:1: error: 'include' does not name a type
 include<cstdio>
 ^
0_0_16612106_26782.cpp: In function 'int main()':
0_0_16612106_26782.cpp:6:17: error: 't' was not declared in this scope
     scanf("%d",&t);
                 ^
0_0_16612106_26782.cpp:6:18: error: 'scanf' was not declared in this scope
     scanf("%d",&t);
                  ^
0_0_16612106_26782.cpp:9:21: error: 'n' was not declared in this scope
         scanf("%d",&n);
                     ^
0_0_16612106_26782.cpp:10:45: error: 'a' was not declared in this scope
         for(int i=1; i<=n; i++) scanf("%d",&a[i]);
                                             ^
0_0_16612106_26782.cpp:14:20: error: 'a' was not declared in this scope
                 if(a[i]>a[j]) ok++;
                    ^
0_0_16612106_26782.cpp:15:45: error: 'printf' was not declared in this scope
         printf("%.6f\n",(double)ok/(n*(n-1)));
                                             ^