Compilare: main.cpp: In function 'int main()': main.cpp:57:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j=0; j<a[x].size(); ++j) ~^~~~~~~~~~~~ main.cpp:27:34: 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); ^ main.cpp:28:36: 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); ^ main.cpp:29:29: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&n,&m,&k); ^ main.cpp:32:29: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&fort[i]); ^ main.cpp:37:36: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&x,&y,&cost); ^