Compilare: user.cpp: In function ‘void dfs(int, int)’: user.cpp:21:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0 ; i < g[act].size() ; ++i) ^ user.cpp:28:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0 ; i < g[act].size() ; ++i) ^ user.cpp: In function ‘void getChains(int)’: user.cpp:41:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0 ; i < g[act].size() ; ++i) ^ user.cpp:47:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0 ; i < g[act].size() ; ++i) ^ user.cpp: In function ‘int main()’: user.cpp:119:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("heavypath.in" , "r" , stdin); ^ user.cpp:120:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("heavypath.out" , "w" , stdout); ^ user.cpp:122:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d" , &n); ^ user.cpp:123:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d" , &q); ^ user.cpp:126:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d" , &x[i]); ^ user.cpp:130:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d" , &a); ^ user.cpp:131:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d" , &b); ^ user.cpp:155:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d" , &t); ^ user.cpp:156:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d" , &a); ^ user.cpp:157:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d" , &b); ^