Compilare: main.cpp: In function 'void prin_castel(int)': main.cpp:29:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int AmCheia = 0; AmCheia<need_keys[MaAflu].size(); AmCheia++) ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:63:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("castel.in", "r", stdin); ^ main.cpp:64:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("castel.out", "w", stdout); ^ main.cpp:65:36: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d\n", &n, &m, &k); ^ main.cpp:70:34: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &a[i][j]); ^