#include <bits/stdc++.h> using namespace std; const long long MOD = 998244353; void rec(const string &s, long long i, string cur, unordered_map<string, long long> &sc) { if(i == s.size()){ if(!cur.empty()) sc[cur]++; return; } rec(s, i + 1, cur, sc); rec(s, i + 1, cur + s[i], sc); } long long count(const string &s) { unordered_map<string, long long> sc; rec(s, 0, "", sc); long long res = 0; for (const auto &p : sc) { if(p.second >= 2) res++; } return res % MOD; } int main(){ cin.tie(0)->sync_with_stdio(0); long long n, q; cin >> n >> q; string s; cin >> s; cout << count(s) << "\n"; for (long long i = 0; i < q; i++){ long long pos; char c; cin >> pos >> c; s[pos - 1] = c; cout << count(s) << "\n"; } }
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 | #include <bits/stdc++.h> using namespace std; const long long MOD = 998244353; void rec(const string &s, long long i, string cur, unordered_map<string, long long> &sc) { if(i == s.size()){ if(!cur.empty()) sc[cur]++; return; } rec(s, i + 1, cur, sc); rec(s, i + 1, cur + s[i], sc); } long long count(const string &s) { unordered_map<string, long long> sc; rec(s, 0, "", sc); long long res = 0; for (const auto &p : sc) { if(p.second >= 2) res++; } return res % MOD; } int main(){ cin.tie(0)->sync_with_stdio(0); long long n, q; cin >> n >> q; string s; cin >> s; cout << count(s) << "\n"; for (long long i = 0; i < q; i++){ long long pos; char c; cin >> pos >> c; s[pos - 1] = c; cout << count(s) << "\n"; } } |