Compilare: user.cpp: In function ‘int main()’: user.cpp:77:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < graf.size(); i++) ^ user.cpp:86:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < apm.size(); i++) ^ user.cpp:53:34: 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:54:36: 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:61:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &k); ^ user.cpp:65:45: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &m.x, &m.y, &m.cost); ^