Compilare: user.cpp: In function ‘int main()’: user.cpp:39:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<dist[c].size(); i++) ^ user.cpp:67:17: warning: array subscript has type ‘char’ [-Wchar-subscripts] pos[S[i]].push_back(i); ^ user.cpp:88:21: warning: array subscript has type ‘char’ [-Wchar-subscripts] pos[S[j]].pop_back(); ^ user.cpp:92:21: warning: array subscript has type ‘char’ [-Wchar-subscripts] pos[S[j]].push_back(j); ^ user.cpp:18:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bignumber.in", "r", stdin); ^ user.cpp:19:42: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bignumber.out", "w", stdout); ^ user.cpp:21:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d\n", &N, &X); ^ user.cpp:22:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s\n", S + 1); ^