题目背景
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题目描述
The N (1 <= N <= 20) cows conveniently numbered 1...N are playing yet another one of their crazy games with Farmer John. The cows will arrange themselves in a line and ask Farmer John what their line number is. In return, Farmer John can give them a line number and the cows must rearrange themselves into that line.
A line number is assigned by numbering all the permutations of the line in lexicographic order.
Consider this example:
Farmer John has 5 cows and gives them the line number of 3.
The permutations of the line in ascending lexicographic order: 1st: 1 2 3 4 5
2nd: 1 2 3 5 4
3rd: 1 2 4 3 5
Therefore, the cows will line themselves in the cow line 1 2 4 3 5.
The cows, in return, line themselves in the configuration '1 2 5 3 4' and ask Farmer John what their line number is.
Continuing with the list:
4th : 1 2 4 5 3
5th : 1 2 5 3 4
Farmer John can see the answer here is 5
Farmer John and the cows would like your help to play their game. They have K (1 <= K <= 10,000) queries that they need help with. Query i has two parts: C_i will be the command, which is either 'P' or 'Q'.
If C_i is 'P', then the second part of the query will be one integer A_i (1 <= A_i <= N!), which is a line number. This is Farmer John challenging the cows to line up in the correct cow line.
If C_i is 'Q', then the second part of the query will be N distinct integers B_ij (1 <= B_ij <= N). This will denote a cow line. These are the cows challenging Farmer John to find their line number.
N(1<=N<=20)头牛，编号为1...N，正在与FJ玩一个疯狂的游戏。奶牛会排成一行（牛线），问FJ此时的行号是多少。之后，FJ会给牛一个行号，牛必须按照新行号排列成线。
行号是通过以字典序对行的所有排列进行编号来分配的。比如说：FJ有5头牛，让他们排为行号3，排列顺序为：
1：1 2 3 4 5
2：1 2 3 5 4
3：1 2 4 3 5
因此，牛将在牛线1 2 4 3 5中。
之后，奶牛排列为“1 2 5 3 4”，并向FJ问他们的行号。继续列表：
4：1 2 4 5 3
5：1 2 5 3 4
FJ可以看到这里的答案是5。
FJ和奶牛希望你的帮助玩他们的游戏。他们需要K(1<=K<=10000)组查询，查询有两个部分：C_i将是“P”或“Q”的命令。
如果C_i是'P'，则查询的第二部分将是一个整数A_i（1 <= A_i <= N！），它是行号。此时，你需要回答正确的牛线。
如果C_i是“Q”，则查询的第二部分将是N个不同的整数B_ij（1 <= B_ij <= N）。这将表示一条牛线，此时你需要输出正确的行号。
输入输出格式
输入格式：
* Line 1: Two space-separated integers: N and K
* Lines 2..2*K+1: Line 2*i and 2*i+1 will contain a single query.
Line 2*i will contain just one character: 'Q' if the cows are lining up and asking Farmer John for their line number or 'P' if Farmer John gives the cows a line number.
If the line 2*i is 'Q', then line 2*i+1 will contain N space-separated integers B_ij which represent the cow line. If the line 2*i is 'P', then line 2*i+1 will contain a single integer A_i which is the line number to solve for.
输出格式：
* Lines 1..K: Line i will contain the answer to query i.
If line 2*i of the input was 'Q', then this line will contain a single integer, which is the line number of the cow line in line 2*i+1.
If line 2*i of the input was 'P', then this line will contain N space separated integers giving the cow line of the number in line 2*i+1.
输入输出样例
5 2 P 3 Q 1 2 5 3 4
1 2 4 3 5 5
恶心的题目
1 //2018-08-05 15:34:58 2 #include <iostream> 3 #include <cstdio> 4 #include <cstring> 5 #include <algorithm> 6 #define int long long 7 using namespace std; 8 9 const int N = 25; 10 long long n, k; 11 long long fac[N], cow[N], a[N], vis[N]; 12 13 signed main(void){ 14 fac[0] = 1; 15 cin >> n >> k; 16 for(int i=1; i<=n;i++) 17 fac[i] = fac[i-1]*i; 18 while(k--){ 19 20 char ch; 21 cin >> ch; 22 //********************** 23 if(ch == 'P'){ 24 long long x; 25 cin >> x; 26 memset(vis, 0, sizeof(vis)); 27 int j; 28 x--; 29 for(int i=1; i<=n; i++){ 30 int t = x/fac[n-i]; //**; 31 for(j=1; j<=n; j++) 32 if(!vis[j]){ 33 if(!t) break; 34 t--; 35 } 36 cout << j << " "; 37 vis[j] = 1; 38 x %= fac[n-i]; 39 } 40 41 printf("\n"); 42 }//**************************************************** 43 else if(ch == 'Q'){ 44 int ans = 0; 45 for(int i=1; i<=n; i++){ 46 cin >> cow[i]; 47 } 48 for(int i=1; i<=n; i++){ 49 int t = 0; 50 for(int j=i+1; j<=n; j++) 51 if(cow[i] > cow[j]) t++; 52 ans += t*fac[n-i]; 53 } 54 55 printf("%lld\n", ans+1); 56 } 57 } 58 59 60 61 return 0; 62 }