题意 给两堆牌s1,s2交给你洗 每堆有c张 每次洗牌得到s12 其中s2的最下面一张在s12的最下面一张然后按顺序一张s1一张s2 洗好之后可以把s12下面的c张做s1 上面的c张做s2 求多少次洗牌之后可以得到输入给你的串s 不能得到输出-1
简单模拟 s1+s2!=s就一直洗牌 如果回到初始状态都没得到s就不会得到s了 得到s就可以输出洗牌次数了
#include<iostream>
#include<string>
using namespace std;
int cas, c, ans;
string s, bs, s12, s1, s2;
void shuf (string s1, string s2)
{
if (bs == s) return;
++ans;
int i = -1, j = -1, k;
string ss1, ss2;
for (k = 0; k < c; ++k)
ss1 += (i == j ? s2[++i] : s1[++j]);
for (k = 0; k < c; ++k)
ss2 += (i == j ? s2[++i] : s1[++j]);
s12 = ss1 + ss2;
if (s12 == s || s12 == bs) return;
else shuf (ss1, ss2);
}
int main()
{
cin >> cas;
for (int ca = 1; ca <= cas; ++ca)
{
ans = 0;
cin >> c >> s1 >> s2 >> s;
bs = s1 + s2;
shuf (s1, s2);
if (s12 != s) ans = -1;
cout << ca << " " << ans << endl;
}
return 0;
}
附上此题数据
/* 11 4 AHAH HAHA HHAAAAHH 3 CDE CDE EEDDCC 9 ACCABCABC DEFDEFDEF ECECECAFAFAFDBDBDB 10 ABCDEFGHCD AAAAAAAAAA BDFHDAAAAAACEGCAAAAA 100 ABCDEFGHCDABCDEFGHCDABCDEFGHCDABCDEFGHCDABCDEFGHCDABCDEFGHCDABCDEFGHCDABCDEFGHCDABCDEFGHCDABCDEFGHCD ABCDEFGHCDABCDEFGHCDABCDEFGHCDABCDEFGHCDABCDEFGHCDABCDEFGHCDABCDEFGHCDABCDEFGHCDABCDEFGHCDABCDEFGHCD CEGCACEGCACEGCACEGCACEGCADFHDBDFHDBDFHDBDFHDBDFHDBEGCACEGCACEGCACEGCACEGCACFHDBDFHDBDFHDBDFHDBDFHDBDGCACEGCACEGCACEGCACEGCACEHDBDFHDBDFHDBDFHDBDFHDBDFCACEGCACEGCACEGCACEGCACEGDBDFHDBDFHDBDFHDBDFHDBDFH 5 AAAAA BBBBB AABBBAAABB 6 AAAAAA BBBBBB AAABBBAAABBB 7 AAAAAAA BBBBBBB ABBAABBAABBAAB 8 AAAAAAAA BBBBBBBB BBAABBAABBAABBAA 9 AAAAAAAAA BBBBBBBBB BBBBAAAAABBBBBAAAA 10 AAAAAAAAAA BBBBBBBBBB BBAABBAABBAABBAABBAA 1 2 2 -1 3 -1 4 5 5 30 6 9 7 11 8 2 9 2 10 8 11 2 */
Shuffle‘m Up
Description
A common pastime for poker players at a poker table is to shuffle stacks of chips. Shuffling chips is performed by starting with two stacks of poker chips, S1 and S2, each stack containing Cchips.
Each stack may contain chips of several different colors.
The actual shuffle operation is performed by interleaving a chip from S1 with a chip from S2 as shown below for C = 5:
The single resultant stack, S12, contains 2 * C chips. The bottommost chip of S12 is the bottommost chip from S2. On top of that chip, is the bottommost
chip from S1. The interleaving process continues taking the 2nd chip from the bottom of S2 and placing that on S12, followed by the 2nd chip from the
bottom of S1 and so on until the topmost chip from S1 is placed on top of S12.
After the shuffle operation, S12 is split into 2 new stacks by taking the bottommost C chips from S12 to form a new S1 and the topmost C chips
from S12 to form a new S2. The shuffle operation may then be repeated to form a new S12.
For this problem, you will write a program to determine if a particular resultant stack S12 can be formed by shuffling two stacks some number of times.
Input
The first line of input contains a single integer N, (1 ≤ N ≤ 1000) which is the number of datasets that follow.
Each dataset consists of four lines of input. The first line of a dataset specifies an integer C, (1 ≤ C ≤ 100) which is the number of chips in each initial stack (S1 and S2).
The second line of each dataset specifies the colors of each of the C chips in stack S1, starting with the bottommost chip. The third line of each dataset specifies the colors of each of the C chips
in stack S2starting with the bottommost chip. Colors are expressed as a single uppercase letter (A through H). There are no blanks or separators between the chip colors. The fourth line of each
dataset contains 2 * C uppercase letters (A through H), representing the colors of the desired result of the shuffling of S1 and S2 zero or
more times. The bottommost chip’s color is specified first.
Output
Output for each dataset consists of a single line that displays the dataset number (1 though N), a space, and an integer value which is the minimum number of shuffle operations required to get the desired resultant stack. If the
desired result can not be reached using the input for the dataset, display the value negative 1 (?1) for the number of shuffle operations.
Sample Input
2 4 AHAH HAHA HHAAAAHH 3 CDE CDE EEDDCC
Sample Output
1 2 2 -1
POJ 3087 Shuffle'm Up（模拟）