题解 | 游游的字符重排

#include <bits/stdc++.h>
using namespace std;
#define endl "\n"
#define all(a) a.begin(), a.end()

void solve() {
    string s;cin >> s;
    int ans = 0;
    sort(all(s));
    do {
        int ok = 0;
        char pre = ' ';
        for (char i : s) {
            if (i == pre) {
                ok = 1;
                break;
            }
            pre = i;
        }
        if (ok == 0)ans++;
    } while (next_permutation(all(s)));
    cout << ans << endl;
}


signed main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);cout.tie(nullptr);
    int t = 1;
    //cin >> t;
    for (int i = 1; i <= t; i++) {
        //cout << "----Test " << i << "----" << endl;
        solve();
    }
    return 0;
}

全排列模拟