Compilare: main.cpp: In function 'int main()': main.cpp:37:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("zvon.in", "rt", stdin); ^ main.cpp:38:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("zvon.out", "wt", stdout); ^ main.cpp:40:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] for(scanf("%d", &T); T; --T) ^ main.cpp:42:33: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] for(scanf("%d", &N), i=1; i<N; ++i) ^ main.cpp:44:35: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &a, &b); ^