Compilare: main.cpp: In function 'int main()': main.cpp:422:12: warning: unused variable 'val' [-Wunused-variable] int N, M, val, t, x, y; ^~~ main.cpp: In member function 'Tinfo segment_tree::SegmentTree<Tinfo, Combiner>::query(int, int) [with Tinfo = int; Combiner = tree_decomposition::DefaultCombiner<int>]': main.cpp:111:11: warning: 'ret_lsh' may be used uninitialized in this function [-Wmaybe-uninitialized] Tinfo ret_lsh, ret_rsh; ^~~~~~~ main.cpp:111:20: warning: 'ret_rsh' may be used uninitialized in this function [-Wmaybe-uninitialized] Tinfo ret_lsh, ret_rsh; ^~~~~~~ main.cpp: In member function 'Tinfo tree_decomposition::TreeDecomposition<Tinfo, Combiner>::query(int, int) [with Tinfo = int; Combiner = tree_decomposition::DefaultCombiner<int>]': main.cpp:361:20: warning: 'ret_dst' may be used uninitialized in this function [-Wmaybe-uninitialized] Tinfo ret_src, ret_dst, ret; ^~~~~~~ main.cpp:361:11: warning: 'ret_src' may be used uninitialized in this function [-Wmaybe-uninitialized] Tinfo ret_src, ret_dst, ret; ^~~~~~~ main.cpp: In member function 'int tree_decomposition::TreeDecomposition<Tinfo, Combiner>::dfs(int) [with Tinfo = int; Combiner = tree_decomposition::DefaultCombiner<int>]': main.cpp:276:14: warning: 'chosen_son' may be used uninitialized in this function [-Wmaybe-uninitialized] path_[what_path_[chosen_son]].array_.push_back(node); ~~~~~^