View Compilation Error

0_0_6591676_31828.cpp: In function `void build(int, int, int)':
0_0_6591676_31828.cpp:61: error: `left' undeclared (first use this function)
0_0_6591676_31828.cpp:61: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_6591676_31828.cpp: In function `int query(int, int, int)':
0_0_6591676_31828.cpp:86: error: `right' undeclared (first use this function)
0_0_6591676_31828.cpp:86: error: 'struct Node' has no member named 'y'
0_0_6591676_31828.cpp:91: error: `left' undeclared (first use this function)