View Compilation Error

0_0_25724328_4189.cpp: In function 'int main()':
0_0_25724328_4189.cpp:16:2: error: 'cin' was not declared in this scope
  cin>>t;
  ^
0_0_25724328_4189.cpp:19:27: error: 'memset' was not declared in this scope
   memset(cnt,0,sizeof(cnt));
                           ^
0_0_25724328_4189.cpp:21:22: error: 'scanf' was not declared in this scope
   scanf("%d%s",&n,A+1);
                      ^
0_0_25724328_4189.cpp:24:9: error: 's' was not declared in this scope
    v=id(s[i]);
         ^