Compilare: user.cpp: In function ‘int main()’: user.cpp:89:15: warning: unused variable ‘left’ [-Wunused-variable] int i, j, left, right; ^ user.cpp:89:21: warning: unused variable ‘right’ [-Wunused-variable] int i, j, left, right; ^ user.cpp: In function ‘std::pair<int, int> read()’: user.cpp:21:13: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(ln); ^ user.cpp: In function ‘int main()’: user.cpp:87:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("adapost.in", "r", stdin); ^ user.cpp:88:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("adapost.out", "w", stdout); ^ user.cpp:91:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n", &n); ^ user.cpp: In function ‘int bs(long long int, long long int)’: user.cpp:83:21: warning: ‘last’ may be used uninitialized in this function [-Wmaybe-uninitialized] return sqrt(last); ^ /tmp/ccOcPlTq.o: In function `read()': user.cpp:(.text+0x27): warning: the `gets' function is dangerous and should not be used.