Compilare: main.cpp: In function 'int main()': main.cpp:10:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("mexitate.in","r",stdin); ^ main.cpp:11:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("mexitate.out","w",stdout); ^ main.cpp:41:21: warning: iteration 399999 invokes undefined behavior [-Waggressive-loop-optimizations] b[z]=0; ~~~~^~ main.cpp:35:27: note: within this loop for (int z=1;z<=400000;z++) ~^~~~~~~~