View Compilation Error

0_0_18436829_30946.cpp: In function 'int main()':
0_0_18436829_30946.cpp:8:5: error: 'cin' was not declared in this scope
     cin>>t;
     ^
0_0_18436829_30946.cpp:11:9: error: 'i' was not declared in this scope
     for(i=0;i<20;i++)
         ^