Eroare de compilare: main.cpp: In function 'void dfs(int, int)': main.cpp:21:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 21 | for ( i = 0; i < child[nod].size(); i++ ) | ~~^~~~~~~~~~~~~~~~~~~ main.cpp: In function 'int read_u32()': main.cpp:48:13: error: 'isdigit' was not declared in this scope 48 | while (!isdigit(c = read_ch()) && c != '-'); | ^~~~~~~ main.cpp:55:12: error: 'isdigit' was not declared in this scope 55 | while (isdigit(c = read_ch())) { | ^~~~~~~ Non zero exit status: 1