Compilare: main.cpp: In function 'int main()': main.cpp:75:18: warning: unused variable 'ok' [-Wunused-variable] bool ok = 0; ^~ main.cpp:67:41: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("harbingers.in", "r", stdin); ^ main.cpp:68:43: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("harbingers.out", "w", stdout); ^ main.cpp:70:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ main.cpp:73:36: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &x, &y, &c); ^ main.cpp:82:61: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] for(int i = 2; i <= n ; ++i) scanf("%d%d", &B[i], &A[i]); ^