Compilare: user.cpp: In function ‘void solve()’: user.cpp:70:9: warning: unused variable ‘i’ [-Wunused-variable] int i, j, x; ^ user.cpp:70:12: warning: unused variable ‘j’ [-Wunused-variable] int i, j, x; ^ user.cpp:70:15: warning: unused variable ‘x’ [-Wunused-variable] int i, j, x; ^ user.cpp: In function ‘void read()’: user.cpp:15:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("origami.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: In function ‘void solve()’: user.cpp:73:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &a, &b); ^ user.cpp: In function ‘void write()’: user.cpp:85:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("origami.out", "w", stdout); ^