Compilare: user.cpp: In function ‘void bfs(std::vector<std::vector<int> >, std::vector<std::vector<int> >&, int, std::ofstream&)’: user.cpp:9:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < v[nod].size(); j++) ^ user.cpp:11:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int q = 0; q < viz[nod].size(); q++) ^ user.cpp: In function ‘int main()’: user.cpp:34:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j = 0; j < v[i].size(); j++) ^ user.cpp:40:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j = 0; j < v[i].size(); j++) ^ user.cpp:42:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int q = 0; q < viz[i].size(); q++) ^ user.cpp:23:30: warning: unused variable ‘flag’ [-Wunused-variable] int n, m, i, j, nod1, nod2, flag = 1; ^ user.cpp:53:17: warning: ignoring return value of ‘int system(const char*)’, declared with attribute warn_unused_result [-Wunused-result] system("PAUSE"); ^