Compilare: user.cpp: In function ‘int main()’: user.cpp:42:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (k=0; k<v[i].size(); k++) ^ user.cpp:49:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (k=0; k<v[j].size(); k++) ^ user.cpp:64:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (k=0; k<v[i].size(); k++) ^ user.cpp:71:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (k=0; k<v[j].size(); k++) ^ user.cpp:83:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (k=0; k<v[i].size(); k++) ^ user.cpp:90:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (k=0; k<v[j].size(); k++) ^ user.cpp:15:30: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cerc.in","r",stdin); ^ user.cpp:16:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cerc.out","w",stdout); ^ user.cpp:17:16: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:20:61: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for (i=1; i<=n; i++) scanf("%d %d %d", &x[i], &y[i], &r[i]); ^