Compilare: user.cpp: In function ‘int main()’: user.cpp:62:8: warning: unused variable ‘res’ [-Wunused-variable] LL res; ^ user.cpp:59:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("balans.in", "r", stdin); ^ user.cpp:60:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("balans.out", "w", stdout); ^ user.cpp:64:38: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d", &n, &m, &r, &c); ^ user.cpp:70:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &a[i][j]); ^ user.cpp: In function ‘long long int bs(long long int, long long int)’: user.cpp:55:12: warning: ‘last’ may be used uninitialized in this function [-Wmaybe-uninitialized] return last; ^ user.cpp: In function ‘int main()’: user.cpp:77:51: warning: ‘last’ may be used uninitialized in this function [-Wmaybe-uninitialized] printf("%.3lf\n", (double)bs(0, valmax) / 1000); ^