View Compilation Error

0_0_29676721_12828.cpp:14:1: error: 't' does not name a type
 t[800005];
 ^
0_0_29676721_12828.cpp: In function 'void Pushup(int)':
0_0_29676721_12828.cpp:17:5: error: 't' was not declared in this scope
     t[k] = max(t[k<<1],t[k<<1|1]);
     ^
0_0_29676721_12828.cpp: In function 'void build(int, int, int)':
0_0_29676721_12828.cpp:22:21: error: 'a' was not declared in this scope
         scanf("%d",&a[k]);
                     ^
0_0_29676721_12828.cpp: In function 'void update(int, int, int, int, int)':
0_0_29676721_12828.cpp:34:9: error: 't' was not declared in this scope
         t[k] = v; 
         ^
0_0_29676721_12828.cpp: In function 'int query(int, int, int, int, int)':
0_0_29676721_12828.cpp:49:16: error: 't' was not declared in this scope
         return t[k];
                ^