Compilare: user.cpp: In function ‘int main()’: user.cpp:82:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dragoni.in","r",stdin); ^ user.cpp:83:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dragoni.out","w",stdout); ^ user.cpp:85:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &nr_case); ^ user.cpp:86:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ user.cpp:89:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &drag[i]); ^ user.cpp:93:39: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &u, &v, &cost); ^ user.cpp:106:22: warning: iteration 804u invokes undefined behavior [-Waggressive-loop-optimizations] if(d[n][i] != INF and d[n][i] < dist_min){ ^ user.cpp:105:9: note: containing loop for(i = 1; i <= 50000; ++i){ ^