Compilare: user.cpp: In function ‘void dijkstra(int)’: user.cpp:59:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < l[x].size(); i++) ^ user.cpp: In function ‘int main()’: user.cpp:24:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("catun.in", "r", stdin); ^ user.cpp:25:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("catun.out", "w",stdout); ^ user.cpp:26:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &n, &m, &k); ^ user.cpp:30:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &f[i]); ^ user.cpp:36:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &x, &y, &z); ^