Compilare: user.cpp: In function ‘void solve()’: user.cpp:115:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j = 0; j < graph [i].size (); ++ j) { ^ user.cpp:124:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j = 0; j < graph [i].size (); ++ j) { ^ user.cpp:145:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j = 0; j < graph [i].size (); ++ j) { ^ user.cpp:170:45: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j = 0; j < graph [i].size () - 1; j ++) { ^ user.cpp:107:18: warning: unused variable ‘ok’ [-Wunused-variable] int i, a, b, ok, edge, flag =0, aux, fx, fy, j, med, aa, bb, k; ^ user.cpp:107:22: warning: unused variable ‘edge’ [-Wunused-variable] int i, a, b, ok, edge, flag =0, aux, fx, fy, j, med, aa, bb, k; ^ user.cpp: In member function ‘void myIfstream::advance()’: user.cpp:29:43: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread (buffer, 1, SIZE, input); ^ user.cpp: In function ‘int main()’: user.cpp:223:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("ulei.out", "w", stdout); ^ user.cpp: In constructor ‘myIfstream::myIfstream(const char*)’: user.cpp:36:39: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread (buffer, 1, SIZE, input); ^