问题 C: ELI'S CURIOUS MIND
时间限制: 1 Sec 内存限制: 128 MB
提交: 54 解决: 46
[提交] [状态] [讨论版] [命题人:admin]
题目描述
Eli is a teenager who loves to study chemistry. She recently joined a chemistry research lab.
Dr. Phil wants her to just play around with some chemicals and observe their reaction.
Therefore, he gave her a one-row tray of test tubes with the different chemical inside of them and told her:
"Mix these chemical together anyhow that you like, but the you have to follow two rules:
1. Never make a mixture that has two chemicals that their tubes are next to each other.
2. Keep adding more chemical to the mixture until it is not violating the new rule. "
For example, in the image you can see she was given 5 tubes and she is able to make 4 different mixture without violating the rule: {1,3,5}, {2,4}, {2,5}, {1,4}.
But she cannot mix 1 and 3 only because she still can add 5 without violating the rules.
She is curious to know how many different mixtures she can make without violating the rule with any given number of tubes. That's why she asks you write a code to calculate it for her.
输入
The input will consist of a sequence of numbers N, 1≤N≤ 76. Each number will be on a separate line. The input will be terminated by 0.
输出
Output the number of different mixture she can make without violating the rule mentioned above on a single line as show in the sample. The number of all subsets will be less than 231 .
样例输入
1 2 3 4 5 30 0
样例输出
Case #1: 0 Case #2: 0 Case #3: 1 Case #4: 3 Case #5: 4 Case #6: 4410
队友：这题没思路，你打个表看看
我：好
3min后
我：这表咋打啊？？？
n min 后
我：表打好了，快来看
队友：嗯，写数组里吧，这题A了
本来想打表找找规律来着，一不小心把答案都打出来了qwq
打表代码
#include <bits/stdc++.h>
typedef long long ll;
using namespace std;
int ans,n;
void dfs(int t)
{
if(t>n)
return;
if(t+2<=n)
{
//printf("%d--->%d,",t,t+2);
if(t+4>n)
ans++;//,printf("\n");
}
dfs(t+2);
if(t+3<=n)
{
//printf("%d--->%d,",t,t+3);
if(t+5>n)
ans++;//,printf("\n");
}
if(t+2<=n)
dfs(t+3);
}
int main()
{
for(int i=1;i<=76;i++)
{
//scanf("%d",&n);
n = i;
ans = 0;
dfs(1);
dfs(2);
printf("%d --->%d\n",i,ans);
}
return 0;
}
好像是递推来着，不管了，暴力过了就是过了
Ac
#include <bits/stdc++.h>
#define inf 0x3f3f3f3f
using namespace std;
typedef long long ll;
int a[100]=
{
0,
0,
0,
1,
3,
4,
5,
7,
9,
12,
16,
21,
28,
37,
49,
65,
86,
114,
151,
200,
265,
351
,465
,616
,816
,1081
,1432
,1897
,2513
,3329
,4410
,5842
,7739
,10252
,13581
,17991
,23833
,31572
,41824
,55405
,73396
,97229
,128801
,170625
,226030
,299426
,396655
,525456
,696081
,922111
,1221537
,1618192
,2143648
,2839729
,3761840
,4983377
,6601569
,8745217
,11584946
,15346786
,20330163
,26931732
,35676949
,47261895
,62608681
,82938844
,109870576
,145547525
,192809420
,255418101
,338356945
,448227521
,593775046
,786584466
,1042002567
,1380359512
,1828587033
};
int main()
{
int n;
int Case=1;
while(~scanf("%d",&n))
{
if(n==0)
break;
printf("Case #%d: %d\n",Case++,a[n]);
}
return 0;
}