Compilare: main.cpp: In function 'void dfs(int)': main.cpp:11:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < g[x].size(); i ++) ~~^~~~~~~~~~~~~ main.cpp: In function 'void dfst(int)': main.cpp:21:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < gt[x].size(); i ++) ~~^~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:59:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j = 0; j < comp[i].size(); j ++) ~~^~~~~~~~~~~~~~~~ main.cpp:30:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("ctc.in", "r", stdin); ^ main.cpp:31:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("ctc.out", "w", stdout); ^ main.cpp:32:27: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &m); ^ main.cpp:35:31: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x, &y); ^