Compilare: main.cpp: In function 'int main()': main.cpp:51:43: warning: array subscript has type 'char' [-Wchar-subscripts] 51 | hash1_s = (hash1_s + 1LL * val[s[i]] * p1[i]) % mod1; | ~~~^ main.cpp:52:43: warning: array subscript has type 'char' [-Wchar-subscripts] 52 | hash2_s = (hash2_s + 1LL * val[s[i]] * p2[i]) % mod2; | ~~~^ main.cpp:55:58: warning: array subscript has type 'char' [-Wchar-subscripts] 55 | hash_pre1[i + 1] = (hash_pre1[i] + 1LL * val[ch[i]] * p1[i]) % mod1; | ~~~~^ main.cpp:56:58: warning: array subscript has type 'char' [-Wchar-subscripts] 56 | hash_pre2[i + 1] = (hash_pre2[i] + 1LL * val[ch[i]] * p2[i]) % mod2; | ~~~~^ main.cpp: In function 'void genp()': main.cpp:21:15: warning: iteration 2000004 invokes undefined behavior [-Waggressive-loop-optimizations] 21 | p1[i] = (1LL * p1[i - 1] * base) % mod1; | ^ main.cpp:20:18: note: within this loop 20 | for(i = 1; i <= nmax; i++){ | ^