hdu 5459 Jesus Is Here (费波纳茨递推)
Time Limit: 1500/1000 MS (Java/Others) Memory Limit: 65535/102400 K (Java/Others)
Total Submission(s): 250 Accepted Submission(s): 169
``But Jesus is here!" the priest intoned. ``Show me your messages."
Fine, the first message is s1=‘‘c" and the second one is s2=‘‘ff".
The i-th message is si=si−2+si−1 afterwards. Let me give you some examples.
s3=‘‘cff", s4=‘‘ffcff" and s5=‘‘cffffcff".
``I found the i-th message's utterly charming," Jesus said.
``Look at the fifth message". s5=‘‘cffffcff" and two ‘‘cff" appear in it.
The distance between the first ‘‘cff" and the second one we said, is 5.
``You are right, my friend," Jesus said. ``Love is patient, love is kind.
It does not envy, it does not boast, it is not proud. It does not dishonor others, it is not self-seeking, it is not easily angered, it keeps no record of wrongs.
Love does not delight in evil but rejoices with the truth.
It always protects, always trusts, always hopes, always perseveres."
Listen - look at him in the eye. I will find you, and count the sum of distance between each two different ‘‘cff" as substrings of the message.
Following T lines, each line contain an integer n (3≤n≤201314), as the identifier of message.
Each line contains an integer equaling to:
where sn as a string corresponding to the n-th message.
题意:s[i] = s[i-1] + s[i-2], s[1] = c, s[2] = ff;
求s[i]中没两个c之间的距离之和
定义:dp[i]表示i所对应的答案, 那么dp[i] = dp[i-1] + dp[i-2] + (s[i-1]中的每个c到s[i-2]中的c的距离)
定义:rd[i]表示s[i]中的每个c到s[i]的末尾的距离
ld[i]表示s[i]中的每个c到s[i]的首位的距离
ls[i]表示s[i]的长度
cnt[i]表示s[i]中c的个数
那么有:
rd[i] = rd[i-1] + rd[i-2] + cnt[i-2] * ls[i-1];
ld[i] = ld[i-1] + ld[i-2] + cnt[i-1] * ls[i-2];
dp[i] = dp[i-1] + dp[i-2] + cnt[i-1] * rd[i-2] + cnt[i-2] * ld[i-1];
dp[i] = dp[i-1] + dp[i-2] + cnt[i-1] * rd[i-2] + cnt[i-2] * ld[i-1];
#include <bits/stdc++.h> using namespace std; const int N = 201413; const int M = 530600414; typedef long long ll; ll dp[N], rd[N], ld[N]; ll ls[N], cnt[N]; void init() { ls[3] = 3; cnt[3] = 1; dp[3] = 0; ls[4] = 5; cnt[4] = 1; dp[4] = 0; rd[3] = 3; ld[3] = 0; rd[4] = 3; ld[4] = 2; for(int i = 5; i < N; ++i) { ls[i] = (ls[i - 1] + ls[i - 2]) % M; cnt[i] = (cnt[i - 1] + cnt[i - 2]) % M; rd[i] = (rd[i - 2] + rd[i - 1] + cnt[i - 2] * ls[i - 1]) % M; ld[i] = (ld[i - 2] + ld[i - 1] + cnt[i - 1] * ls[i - 2]) % M; dp[i] = (dp[i - 1] + dp[i - 2] + cnt[i - 1] * rd[i - 2] + cnt[i - 2] * ld[i - 1]) % M; } } int main() { int _, cas = 1; scanf("%d", &_); init(); while(_ --) { int n; scanf("%d", &n); printf("Case #%d: %lld\n",cas++, dp[n] % M); } return 0; }
Time Limit: 1500/1000 MS (Java/Others) Memory Limit: 65535/102400 K (Java/Others)
Total Submission(s): 250 Accepted Submission(s): 169
``But Jesus is here!" the priest intoned. ``Show me your messages."
Fine, the first message is s1=‘‘c" and the second one is s2=‘‘ff".
The i-th message is si=si−2+si−1 afterwards. Let me give you some examples.
s3=‘‘cff", s4=‘‘ffcff" and s5=‘‘cffffcff".
``I found the i-th message's utterly charming," Jesus said.
``Look at the fifth message". s5=‘‘cffffcff" and two ‘‘cff" appear in it.
The distance between the first ‘‘cff" and the second one we said, is 5.
``You are right, my friend," Jesus said. ``Love is patient, love is kind.
It does not envy, it does not boast, it is not proud. It does not dishonor others, it is not self-seeking, it is not easily angered, it keeps no record of wrongs.
Love does not delight in evil but rejoices with the truth.
It always protects, always trusts, always hopes, always perseveres."
Listen - look at him in the eye. I will find you, and count the sum of distance between each two different ‘‘cff" as substrings of the message.
Following T lines, each line contain an integer n (3≤n≤201314), as the identifier of message.
Each line contains an integer equaling to:
where sn as a string corresponding to the n-th message.