Compilare: main.cpp: In function 'void solve(int, int, long long int)': main.cpp:86:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < a[ind[nod]].size() ; ++i){ ~~^~~~~~~~~~~~~~~~~~~~ main.cpp:116:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < a[ind[it]].size() ; ++i){ ~~^~~~~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:136:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("pensula.in", "r", stdin); ^ main.cpp:137:40: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("pensula.out", "w", stdout); ^ main.cpp:139:40: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%lld%d%d", &n, &m, &q, &C); ^ main.cpp:143:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &x); ^