Compilare: user.cpp: In function ‘void BFS()’: user.cpp:25:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < G[j].size(); i++) ^ user.cpp:59:45: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < fathers[j].size(); i++) ^ user.cpp: In function ‘int main()’: user.cpp:93:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < sol.size(); i++) ^ user.cpp:76:43: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f1, "%d%d%d%d", &n, &m, &x, &y); ^ user.cpp:79:35: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f1, "%d%d", &a, &b); ^