Compilare: main.cpp: In function 'int main(int, const char**)': main.cpp:23:18: warning: unused variable 'j' [-Wunused-variable] int n, m, i, j, x, y, step, cnt, sol; ^ main.cpp:25:29: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen(FIN, "r", stdin); ^ main.cpp:26:31: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen(FOUT, "w", stdout); ^ main.cpp:37:38: warning: iteration 100098 invokes undefined behavior [-Waggressive-loop-optimizations] for(i = 2; i <= nmax; ++i) lg[i] = lg[i/2] + 1; ~~~~~~^~~~~~~~~~~~~ main.cpp:37:18: note: within this loop for(i = 2; i <= nmax; ++i) lg[i] = lg[i/2] + 1; ~~^~~~~~~