Compilare: user.cpp: In function ‘int B()’: user.cpp:56:33: warning: variable ‘sol’ set but not used [-Wunused-but-set-variable] int left = 1 , right = 1e9, sol = 0; ^ user.cpp: In function ‘int main()’: user.cpp:68:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dragoni.in", "r", stdin); ^ user.cpp:69:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dragoni.out", "w", stdout); ^ user.cpp:71:39: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n%d %d", &instr, &n, &m); ^ user.cpp:73:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &dragon[i]); ^ user.cpp:78:41: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d", &x, &y, &cost); ^