Compilare: main.cpp: In function 'int main()': main.cpp:52:43: warning: array subscript has type 'char' [-Wchar-subscripts] 52 | hash1_s = (hash1_s + 1LL * val[s[i]] * p1[i]) % mod1; | ~~~^ main.cpp:56:64: warning: array subscript has type 'char' [-Wchar-subscripts] 56 | hash_pre1[i + 1] = 1LL * (hash_pre1[i] + 1LL * val[ch[i]] * p1[i]) % mod1; | ~~~~^ main.cpp:44:28: warning: unused variable 'hash2_s' [-Wunused-variable] 44 | long long hash1_s = 0, hash2_s = 0; | ^~~~~~~ main.cpp: In function 'void genp()': main.cpp:22:15: warning: iteration 2000004 invokes undefined behavior [-Waggressive-loop-optimizations] 22 | p1[i] = (1LL * p1[i - 1] * base) % mod1; | ^ main.cpp:21:18: note: within this loop 21 | for(i = 1; i <= nmax; i++){ | ^