Compilare: user.cpp: In function ‘int main()’: user.cpp:34:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < out[vertex1].size(); ++i) ~~^~~~~~~~~~~~~~~~~~~~~ user.cpp:12:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dijkstra.in", "r", stdin); ^ user.cpp:13:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dijkstra.out", "w", stdout); ^ user.cpp:15:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:16:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &m); ^ user.cpp:17:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &s); ^ user.cpp:24:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &a); ^ user.cpp:25:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &b); ^