Compilare: main.cpp: In function 'void solve()': main.cpp:71:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (adj[i].size() < k) { ~~~~~~~~~~~~~~^~~ main.cpp: In function 'int main()': main.cpp:107:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen ("zone2.in", "r", stdin); ^ main.cpp:108:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen ("zone2.out", "w", stdout); ^ main.cpp:110:31: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf ("%d%d%d", &n, &m, &k); ^ main.cpp:111:28: warning: ignoring return value of 'char* fgets(char*, int, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fgets (a[0], NMAX, stdin); ^ main.cpp:113:34: warning: ignoring return value of 'char* fgets(char*, int, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fgets (a[i] + 1, NMAX, stdin); ^