Compilare: main.cpp: In function 'int main()': main.cpp:44:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("ssnd.in", "r", stdin); ^ main.cpp:45:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("ssnd.out", "w", stdout); ^ main.cpp:48:22: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n", &t); ^ main.cpp:51:26: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n", &n); ^ main.cpp: In function 'void eratostene()': main.cpp:14:19: warning: iteration 1000003 invokes undefined behavior [-Waggressive-loop-optimizations] if(!ciur[d]) ~~~~~~^ main.cpp:13:18: note: within this loop for(int d=2;d<=N;d++) ^