Submission #1691565
Source Code Expand
#include <stdio.h> #include <iostream> #include <algorithm> #include <memory.h> using namespace std; typedef long long LL; const int maxn = 1000005; const int mod = 1e9+7; LL dp[maxn],s[maxn],ans;int n; int main() { #ifdef Amberframe freopen("arc071f.in","r",stdin); freopen("arc071f.out","w",stdout); #endif scanf("%d",&n); dp[0]=s[0]=1;ans=1; for (int i=1;i<=n;i++) { dp[i]=((i>=3?s[i-3]:0)+dp[i-1])%mod; s[i]=(s[i-1]+dp[i])%mod; } LL w=(LL)(n-1)*(n-1)%mod; for (int i=1;i<=n;i++) { if (i>=4) ans=(ans+s[i-4])%mod; if (i==n) { ans=(ans+dp[i-1]*(n-1))%mod; } else if (i==n-1) { ans=(ans+dp[i-1]*(n-1))%mod; ans=(ans+dp[i-1]*w)%mod; } else { ans=(ans+dp[i-1]*(LL)(i+1))%mod; ans=(ans+dp[i-1]*w)%mod; } } printf("%lld",ans); return 0; }
Submission Info
Submission Time | |
---|---|
Task | F - Infinite Sequence |
User | Amberframe |
Language | C++14 (GCC 5.4.1) |
Score | 1000 |
Code Size | 828 Byte |
Status | AC |
Exec Time | 23 ms |
Memory | 15872 KB |
Compile Error
./Main.cpp: In function ‘int main()’: ./Main.cpp:19:16: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^
Judge Result
Set Name | Sample | All | ||||
---|---|---|---|---|---|---|
Score / Max Score | 0 / 0 | 1000 / 1000 | ||||
Status |
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Set Name | Test Cases |
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Sample | 0_000.txt, 0_001.txt |
All | 0_000.txt, 0_001.txt, max_1000000.txt, max_999745.txt, max_999880.txt, max_999999.txt, min_1.txt, rnd_14.txt, rnd_22.txt, rnd_25002.txt, rnd_2956.txt, rnd_3.txt, rnd_380467.txt, rnd_407774.txt, rnd_52228.txt, rnd_68.txt, rnd_804783.txt, rnd_85984.txt, rnd_894324.txt, rnd_93.txt, rnd_963981.txt, rnd_968416.txt |
Case Name | Status | Exec Time | Memory |
---|---|---|---|
0_000.txt | AC | 2 ms | 2304 KB |
0_001.txt | AC | 16 ms | 14592 KB |
max_1000000.txt | AC | 23 ms | 15872 KB |
max_999745.txt | AC | 23 ms | 15872 KB |
max_999880.txt | AC | 23 ms | 15872 KB |
max_999999.txt | AC | 23 ms | 15872 KB |
min_1.txt | AC | 2 ms | 2304 KB |
rnd_14.txt | AC | 2 ms | 2304 KB |
rnd_22.txt | AC | 2 ms | 2304 KB |
rnd_25002.txt | AC | 2 ms | 2432 KB |
rnd_2956.txt | AC | 2 ms | 2304 KB |
rnd_3.txt | AC | 2 ms | 2304 KB |
rnd_380467.txt | AC | 11 ms | 10496 KB |
rnd_407774.txt | AC | 11 ms | 10496 KB |
rnd_52228.txt | AC | 3 ms | 4736 KB |
rnd_68.txt | AC | 2 ms | 2304 KB |
rnd_804783.txt | AC | 20 ms | 14592 KB |
rnd_85984.txt | AC | 4 ms | 4992 KB |
rnd_894324.txt | AC | 21 ms | 15104 KB |
rnd_93.txt | AC | 2 ms | 2304 KB |
rnd_963981.txt | AC | 23 ms | 15616 KB |
rnd_968416.txt | AC | 23 ms | 15616 KB |