Compilare: main.cpp: In function 'void bell()': main.cpp:93:18: warning: unused variable 'ok' [-Wunused-variable] bool ok = 0; ^~ main.cpp: In function 'int main()': main.cpp:115:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("rtd.in", "r", stdin); ^ main.cpp:116:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("rtd.out", "w", stdout); ^ main.cpp:119:40: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d", &n, &m, &xa, &ya); ^ main.cpp:125:32: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &x, &y, &k); ^ main.cpp:127:27: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &c[i]); ^ main.cpp:130:30: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &X, &Y); ^