View Compilation Error

0_0_33933213_22236.cpp:46:12: error: expected ')' before ']' token
 }tree[(maxn];     
            ^
0_0_33933213_22236.cpp:46:13: error: expected ']' before ';' token
 }tree[(maxn];     
             ^
0_0_33933213_22236.cpp: In function 'void build(int, int, int)':
0_0_33933213_22236.cpp:53:5: error: 'tree' was not declared in this scope
     tree[rt].l = l;tree[rt].r = r;
     ^
0_0_33933213_22236.cpp: In function 'void push_up(int)':
0_0_33933213_22236.cpp:63:8: error: 'tree' was not declared in this scope
     if(tree[rt].s)tree[rt].len = p[tree[rt].r]-p[tree[rt].l-1];
        ^
0_0_33933213_22236.cpp: In function 'void update(int, int, int, int, int, int)':
0_0_33933213_22236.cpp:69:9: error: 'tree' was not declared in this scope
         tree[rt].s+=val;
         ^
0_0_33933213_22236.cpp: In function 'void solve()':
0_0_33933213_22236.cpp:99:33: error: 'tree' was not declared in this scope
         area+=(a[i+1].h-a[i].h)*tree[1].len;
                                 ^