View Compilation Error

0_0_33584930_19496.cpp: In function 'int main()':
0_0_33584930_19496.cpp:60:52: error: 't' was not declared in this scope
             for(; h + 1 < tail && Y(Q[tail - 1], Q[t]) * X(Q[t], cur) >= X(Q[t - 1], Q[t]) * Y(Q[t], cur); tail--);
                                                    ^
0_0_33584930_19496.cpp:61:17: error: 't' was not declared in this scope
             Q[++t] = cur;
                 ^