luoguP3014 [USACO11FEB]牛线Cow Line

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int maxn=25;
ll a[maxn],jie[maxn];
int main(){
    int n,m;
    scanf("%d%d",&n,&m);
    jie[0]=1;
    for(int i=1;i<=n;++i)jie[i]=jie[i-1]*i;
    for(int i=1;i<=m;++i){
        char opt[2];
        scanf("%s",opt);
        if(opt[0]==‘P‘){
            ll k;
            scanf("%lld",&k);
            k--;
            vector<int>v;
            for(int i=1;i<=n;++i)v.push_back(i);
            for(int i=1;i<=n;++i){
                int t1=k/jie[n-i];
                k%=jie[n-i];
                a[i]=v[t1];
                v.erase(v.begin()+t1);
            }
            for(int i=1;i<=n;++i)printf("%d ",a[i]);
            printf("\n");
        }
        else{
            ll ans=0;
            for(int i=1;i<=n;++i){
                scanf("%lld",&a[i]);
                int t1=a[i],t2=a[i];
                for(int j=1;j<=i;++j){
                    if(a[j]<=t1)--t2;
                }
                ans+=t2*jie[n-i];
            }
            printf("%lld\n",ans+1);
        }
    }
    return 0;
}