foo.cpp: In function 'int RMQ(int)':
foo.cpp:26:1: warning: no return statement in function returning non-void [-Wreturn-type]
 }
 ^
foo.cpp: At global scope:
foo.cpp:27:22: error: ISO C++ forbids declaration of 'query_RMQ' with no type [-fpermissive]
 query_RMQ(int L,int R)
                      ^