Compilare: user.cpp: In function ‘void dfs(int, int)’: user.cpp:11:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0; j<a[i].size(); ++j){ ^ user.cpp: In function ‘int p(int, int)’: user.cpp:22:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=1; i<a[r].size(); ++i){ ^ user.cpp: In function ‘int main()’: user.cpp:31:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("iepuri2.in", "r", stdin); ^ user.cpp:32:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("iepuri2.out", "w", stdout); ^ user.cpp:33:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &k); ^ user.cpp:35:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &r, &l); ^ user.cpp:38:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &j, &l); ^