Compilare: user.cpp: In function ‘void read()’: user.cpp:51:42: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ( "vopsire.in", "r", stdin ) ; ^ user.cpp:52:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ( "%d %d", &M, &N ) ; ^ user.cpp:55:49: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ( "%d %d %d %d", &a, &b, &c, &d ) ; ^ user.cpp:63:76: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ( "%d %d", &x, &y ), A[i].x1 = x, A[i].x2 = y, A[i].type = i ; ^