Compilare: main.cpp: In function 'int main()': main.cpp:20:11: warning: array subscript has type 'char' [-Wchar-subscripts] 20 | f[s[1]]++, fsum[s[1]]++; | ^ main.cpp:20:25: warning: array subscript has type 'char' [-Wchar-subscripts] 20 | f[s[1]]++, fsum[s[1]]++; | ^ main.cpp:22:15: warning: array subscript has type 'char' [-Wchar-subscripts] 22 | f[s[i]]++; | ^ main.cpp:23:67: warning: array subscript has type 'char' [-Wchar-subscripts] 23 | (dp[i] = dp[i - 1] + (i * (i + 1) / 2) + mod - i * (f[s[i]]) + fsum[s[i]]) %= mod; | ^ main.cpp:23:81: warning: array subscript has type 'char' [-Wchar-subscripts] 23 | (dp[i] = dp[i - 1] + (i * (i + 1) / 2) + mod - i * (f[s[i]]) + fsum[s[i]]) %= mod; | ^