85 lines
1.5 KiB
C++
85 lines
1.5 KiB
C++
#include <bits/stdc++.h> // {{{
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// https://codeforces.com/blog/entry/96344
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#pragma GCC optimize("O2,unroll-loops")
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#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
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using namespace std;
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template <typename T>
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constexpr T MIN = std::numeric_limits<T>::min();
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template <typename T>
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constexpr T MAX = std::numeric_limits<T>::max();
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template <typename T>
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[[nodiscard]] static T sc(auto&& x) {
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return static_cast<T>(x);
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}
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template <typename T>
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[[nodiscard]] static T sz(auto&& x) {
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return static_cast<T>(x.size());
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}
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using ll = long long;
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using ld = long double;
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template <typename T>
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using vec = std::vector<T>;
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template <typename T, size_t N>
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using arr = std::array<T, N>;
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#define ff first
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#define ss second
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#define eb emplace_back
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#define pb push_back
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#define all(x) (x).begin(), (x).end()
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#define rall(x) (x).rbegin(), (x).rend()
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// }}}
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void backtrack(vec<int>& freq, string& cur, vector<string>& ans, int len) {
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if (sz<int>(cur) == len) {
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ans.eb(cur);
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return;
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}
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for (int i = 0; i < sz<int>(freq); ++i) {
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if (freq[i] == 0)
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continue;
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--freq[i];
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cur.push_back(i + 'a');
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backtrack(freq, cur, ans, len);
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cur.pop_back();
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++freq[i];
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}
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}
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void solve() {
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string s;
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cin >> s;
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vec<int> m(26, 0);
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int len = s.size();
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for (auto c : s)
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++m[c - 'a'];
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string cur = "";
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vec<string> ans;
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backtrack(m, cur, ans, len);
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cout << ans.size() << endl;
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for (auto& S : ans) {
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cout << S << endl;
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}
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}
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int main() { // {{{
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cin.tie(nullptr)->sync_with_stdio(false);
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solve();
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return 0;
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}
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// }}}
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