Compilare: user.cpp: In function ‘int find(int)’: user.cpp:36:6: warning: unused variable ‘ret’ [-Wunused-variable] int ret; ^ user.cpp: In function ‘int main()’: user.cpp:89:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < adj.size(); i++){ ^ user.cpp:100:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < ans.size(); i++){ ^ user.cpp:75:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("apm.in", "r", stdin); ^ user.cpp:76:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("apm.out", "w", stdout); ^ user.cpp:77:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ user.cpp:83:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &x, &y, &c); ^