[BZOJ] 3301: [USACO2011 Feb] Cow Line

康拓展开/逆展开 模板

#include<algorithm>
#include<iostream>
#include<cstdio>
#define int long long

using namespace std;

inline int rd(){
  int ret=0,f=1;char c;
  while(c=getchar(),!isdigit(c))f=c=='-'?-1:1;
  while(isdigit(c))ret=ret*10+c-'0',c=getchar();
  return ret*f;
}
#define space() putchar(' ')
#define nextline() putchar('\n')
void pot(int x){if(!x)return;pot(x/10);putchar('0'+x%10);}
void out(int x){if(!x)putchar('0');if(x<0)putchar('-'),x=-x;pot(x);}

const int MAXN = 24;

int n,m;

int fac[MAXN],a[MAXN];

int vis[MAXN],tim;
void ct(int x){
	x--;
	++tim;
	for(int i=1;i<=n;i++){
		int cur=x/fac[n-i],j;
		for(j=1;j<=n;j++){
			if(vis[j]==tim)continue;
			if(cur==0) break;
			cur--;
		}
		vis[j]=tim;
		out(j);space();
		x%=fac[n-i];
	}
	nextline();
}

void rct(){
	int ans=1;
	for(int i=1;i<=n;i++){
		int tmp=0;
		for(int j=i+1;j<=n;j++){
			if(a[j]<a[i])tmp++;
		}
		ans+=fac[n-i]*tmp;
	}
	out(ans);nextline();
}

signed main(){
	n=rd();m=rd();
	fac[0]=1;
	for(int i=1;i<=n;i++) fac[i]=fac[i-1]*i;
	char s[MAXN];
	int x;
	for(int i=1;i<=m;i++){
		scanf("%s",s);
		if(s[0]=='P'){
			x=rd();
			ct(x);
		}else{
			for(int j=1;j<=n;j++)a[j]=rd();
			rct();
		}
	}
	return 0;
}