Compilare: user.cpp: In function ‘void solve()’: user.cpp:31:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < x.size(); ++ i) ^ user.cpp: In function ‘void read()’: user.cpp:21:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("harta2.in", "r", stdin); ^ user.cpp:22:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:25:41: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x[i].f, &x[i].s); ^ user.cpp: In function ‘void write()’: user.cpp:60:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("harta2.out", "w", stdout); ^