View Compilation Error

0_0_29208805_10802.cpp: In function 'int main()':
0_0_29208805_10802.cpp:4:5: error: 'a' was not declared in this scope
     a[1]=3,a[2]=7;
     ^
0_0_29208805_10802.cpp:9:17: error: 't' was not declared in this scope
     scanf("%d",&t);
                 ^
0_0_29208805_10802.cpp:12:21: error: 'n' was not declared in this scope
         scanf("%d",&n);
                     ^