Compilare: user.cpp: In function ‘void reverseGraph()’: user.cpp:34:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < edges.size(); i ++) { ^ user.cpp:38:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; i < edges.size(); i ++) { ^ user.cpp:39:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < edges[i].size(); j ++) { ^ user.cpp: In function ‘int main()’: user.cpp:101:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < sol.size(); i ++) { ^ user.cpp:107:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < sol.size(); i ++) { ^ user.cpp:109:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < sol[i].size(); j ++) { ^ user.cpp:61:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("retele.in", "r", stdin); ^ user.cpp:62:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("retele.out", "w", stdout); ^ user.cpp:66:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &m); ^ user.cpp:75:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &a, &b); ^