Compilare: user.cpp: In function ‘int main()’: user.cpp:43:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0; j<bands.size() && bands[j].right < i; j++); ^ user.cpp:28:15: warning: unused variable ‘val’ [-Wunused-variable] int n, i, val, cpy, j, k, maxx=0; ^ user.cpp:28:20: warning: unused variable ‘cpy’ [-Wunused-variable] int n, i, val, cpy, j, k, maxx=0; ^ user.cpp:28:28: warning: unused variable ‘k’ [-Wunused-variable] int n, i, val, cpy, j, k, maxx=0; ^ user.cpp:25:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("heavymetal.in", "r", stdin); ^ user.cpp:26:43: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("heavymetal.out", "w", stdout); ^ user.cpp:30:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:33:48: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &band.left, &band.right); ^