Compilare: main.cpp: In function 'void calc_ciur()': main.cpp:21:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < prime.size() && prime[i] <= ciur[nr] && prime[i] * nr <= LMAX; i++) ~~^~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:40:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("prefix.in", "r", stdin); ^ main.cpp:41:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("prefix.out", "w", stdout); ^ main.cpp:46:19: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d ", &t); ^ main.cpp:48:23: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%s", s + 1); ^