Compilare: main.cpp: In function 'int main()': main.cpp:17:11: warning: array subscript has type 'char' [-Wchar-subscripts] 17 | f[s[1]]++, fsum[s[1]]++; | ^ main.cpp:17:25: warning: array subscript has type 'char' [-Wchar-subscripts] 17 | f[s[1]]++, fsum[s[1]]++; | ^ main.cpp:19:15: warning: array subscript has type 'char' [-Wchar-subscripts] 19 | f[s[i]]++; | ^ main.cpp:20:78: warning: array subscript has type 'char' [-Wchar-subscripts] 20 | (dp[i] = (dp[i - 1] + ((i * (i + 1) / 2) % mod)) % mod - (i * (f[s[i]])) % mod + fsum[s[i]]) %= mod; | ^ main.cpp:20:99: warning: array subscript has type 'char' [-Wchar-subscripts] 20 | (dp[i] = (dp[i - 1] + ((i * (i + 1) / 2) % mod)) % mod - (i * (f[s[i]])) % mod + fsum[s[i]]) %= mod; | ^