Compilare: user.cpp: In function ‘void solve()’: user.cpp:131:9: warning: unused variable ‘p’ [-Wunused-variable] int p, i; ^ user.cpp: In function ‘void read()’: user.cpp:83:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("zc.in", "r", stdin); ^ user.cpp:84:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &m); ^ user.cpp:89:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &cx, &cy); ^ user.cpp: In function ‘void solve()’: user.cpp:139:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("\n%c %d", &d, &x); ^ user.cpp: In function ‘void write()’: user.cpp:170:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("zc.out", "w", stdout); ^ user.cpp: In function ‘void solve()’: user.cpp:165:18: warning: ‘b’ may be used uninitialized in this function [-Wmaybe-uninitialized] ans += b - a; ^ user.cpp:165:18: warning: ‘a’ may be used uninitialized in this function [-Wmaybe-uninitialized]