Compilare: user.cpp: In member function ‘bool flowClass::path()’: user.cpp:30:45: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0 ; i < g[q0].size() ; ++i) ^ user.cpp: In member function ‘void flowClass::work()’: user.cpp:63:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0 ; i < g[sink].size() ; ++i) ^ user.cpp: In function ‘void scan()’: user.cpp:95:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d" , &solve.sink); ^ user.cpp:96:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d" , &m); ^ user.cpp:101:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d" , &u); ^ user.cpp:102:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d" , &v); ^ user.cpp:103:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d" , &x); ^ user.cpp: In function ‘int main()’: user.cpp:111:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("maxflow.in" , "r" , stdin); ^ user.cpp:112:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("maxflow.out" , "w" , stdout); ^ user.cpp:66:40: warning: ‘w0’ may be used uninitialized in this function [-Wmaybe-uninitialized] if (c[d0][sink] == f[w0][q0]) continue; ^ user.cpp:60:23: note: ‘w0’ was declared here int q0 , d0 , w0 , t; ^ user.cpp:66:40: warning: ‘q0’ may be used uninitialized in this function [-Wmaybe-uninitialized] if (c[d0][sink] == f[w0][q0]) continue; ^ user.cpp:60:13: note: ‘q0’ was declared here int q0 , d0 , w0 , t; ^