Compilare: main.cpp: In function 'void solve()': main.cpp:37:27: warning: array subscript has type 'char' [-Wchar-subscripts] nxt[i] = last[a[i]]; ^ main.cpp:38:18: warning: array subscript has type 'char' [-Wchar-subscripts] last[a[i]] = i; ^ main.cpp:64:23: warning: array subscript has type 'char' [-Wchar-subscripts] int p = last[c]; ^ main.cpp: In function 'int main()': main.cpp:75:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("kss.in", "r", stdin); ^ main.cpp:76:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("kss.out", "w", stdout); ^