Compilare: user.cpp: In function ‘void solve()’: user.cpp:31:9: warning: unused variable ‘p’ [-Wunused-variable] int p, q, i, j; ^ user.cpp:31:12: warning: unused variable ‘q’ [-Wunused-variable] int p, q, i, j; ^ user.cpp: In function ‘void read()’: user.cpp:15:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("mayonaka.in", "r", stdin); ^ user.cpp:16:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &m); ^ user.cpp:18:65: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d %d", &v[i].x, &v[i].y, &v[i].s, &v[i].k); ^ user.cpp: In function ‘void write()’: user.cpp:61:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("mayonaka.out", "w", stdout); ^