View Compilation Error

0_0_25385529_15573.cpp: In member function 'void RMQ::init(double*, int)':
0_0_25385529_15573.cpp:25:17: error: 'stmin' was not declared in this scope
     stmax[i][0]=stmin[i][0]=a[i];
                 ^
0_0_25385529_15573.cpp: In member function 'void RMQ::build()':
0_0_25385529_15573.cpp:35:4: error: 'stmin' was not declared in this scope
    stmin[i][j]=min(stmin[i][j-1],stmin[i+(1<<(j-1))][j-1]);
    ^