Submission #1734758
Source Code Expand
#include<stdio.h> #include<math.h> #include<algorithm> #include<queue> #include<deque> #include<string> #include<string.h> #include<vector> #include<set> #include<map> #include<stdlib.h> using namespace std; const long long mod=1000000007; const long long inf=mod*mod; vector<int>g[1100]; long long dp[1100][1100]; int bfs[1100]; int pr[1100]; int dep[1100]; int D; int T=510; int lis[1100]; int dist[1100]; int dc(int a,int b){ int ret=0; int f=0; for(int i=0;i<g[a].size();i++){ if(b==g[a][i])continue; dist[g[a][i]]=dist[a]+1; int q=dc(g[a][i],a)+1; ret=max(ret,q); } return ret; } void dfs(int a,int b){ for(int i=-(D-dist[a]);i<=D-dist[a];i++){ dp[a][T+i]=1; } for(int i=0;i<g[a].size();i++){ if(g[a][i]==b)continue; dfs(g[a][i],a); for(int j=0;j<1100;j++){ long long tmp=0; if(j)tmp=(tmp+dp[g[a][i]][j-1])%mod; if(j+1<1100)tmp=(tmp+dp[g[a][i]][j+1])%mod; dp[a][j]=dp[a][j]*tmp%mod; } } } int n; long long calc(int a){ dist[a]=0; dc(a,-1); for(int i=0;i<n;i++)for(int j=0;j<1100;j++)dp[i][j]=0; dfs(a,-1); long long ret=0; for(int i=0;i<1100;i++){ ret=(ret+dp[a][i])%mod; } return ret; } int main(){ int a; scanf("%d",&a); n=a; for(int i=0;i<a-1;i++){ int p,q;scanf("%d%d",&p,&q);p--;q--; g[p].push_back(q); g[q].push_back(p); } long long r=1; for(int i=0;i<a-1;i++)r=r*2%mod; queue<int>Q; Q.push(0); for(int i=0;i<a;i++)bfs[i]=-1; bfs[0]=0; while(Q.size()){ int at=Q.front(); Q.pop(); for(int i=0;i<g[at].size();i++){ int to=g[at][i]; if(bfs[to]!=-1)continue; bfs[to]=bfs[at]+1; Q.push(to); } } int sz=0; int mv=0; for(int i=0;i<a;i++){ if(bfs[mv]<bfs[i])mv=i; } for(int i=0;i<a;i++)bfs[i]=-1; Q.push(mv); bfs[mv]=0; pr[mv]=-1; while(Q.size()){ int at=Q.front();Q.pop(); for(int i=0;i<g[at].size();i++){ int to=g[at][i]; if(bfs[to]!=-1)continue; Q.push(to); bfs[to]=bfs[at]+1; pr[to]=at; } } int di=0; int da=0; for(int i=0;i<a;i++){ if(di<bfs[i]){ di=bfs[i]; da=i; } } int at=da; while(~at){ lis[sz++]=at; at=pr[at]; } long long ret; if(di%2==0){ D=sz/2; ret=calc(lis[sz/2]); }else{ D=(sz+1)/2; ret=(calc(lis[sz/2-1])+calc(lis[sz/2]))%mod; g[n].push_back(lis[sz/2-1]); g[n].push_back(lis[sz/2]); for(int i=0;i<g[lis[sz/2-1]].size();i++){ if(g[lis[sz/2-1]][i]==lis[sz/2])g[lis[sz/2-1]][i]=n; } for(int i=0;i<g[lis[sz/2]].size();i++){ if(g[lis[sz/2]][i]==lis[sz/2-1])g[lis[sz/2]][i]=n; } ret=(ret+mod-calc(n))%mod; } printf("%lld\n",ret); }
Submission Info
Submission Time | |
---|---|
Task | D - Oriented Tree |
User | tozangezan |
Language | C++14 (GCC 5.4.1) |
Score | 1800 |
Code Size | 2656 Byte |
Status | AC |
Exec Time | 24 ms |
Memory | 8960 KB |
Compile Error
./Main.cpp: In function ‘int main()’: ./Main.cpp:64:16: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&a); ^ ./Main.cpp:67:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] int p,q;scanf("%d%d",&p,&q);p--;q--; ^
Judge Result
Set Name | Sample | All | ||||
---|---|---|---|---|---|---|
Score / Max Score | 0 / 0 | 1800 / 1800 | ||||
Status |
|
|
Set Name | Test Cases |
---|---|
Sample | 0_00.txt, 0_01.txt, 0_02.txt, 0_03.txt |
All | 0_00.txt, 0_01.txt, 0_02.txt, 0_03.txt, 1_00.txt, 1_01.txt, 1_02.txt, 1_03.txt, 1_04.txt, 1_05.txt, 1_06.txt, 1_07.txt, 1_08.txt, 1_09.txt, 1_10.txt, 1_11.txt, 1_12.txt, 1_13.txt, 1_14.txt, 1_15.txt, 1_16.txt, 1_17.txt, 1_18.txt, 1_19.txt, 1_20.txt, 1_21.txt, 1_22.txt, 1_23.txt, 1_24.txt, 1_25.txt, 1_26.txt, 1_27.txt, 1_28.txt |
Case Name | Status | Exec Time | Memory |
---|---|---|---|
0_00.txt | AC | 1 ms | 384 KB |
0_01.txt | AC | 1 ms | 384 KB |
0_02.txt | AC | 1 ms | 384 KB |
0_03.txt | AC | 1 ms | 384 KB |
1_00.txt | AC | 1 ms | 256 KB |
1_01.txt | AC | 11 ms | 8960 KB |
1_02.txt | AC | 24 ms | 8960 KB |
1_03.txt | AC | 11 ms | 8960 KB |
1_04.txt | AC | 23 ms | 8960 KB |
1_05.txt | AC | 11 ms | 8832 KB |
1_06.txt | AC | 23 ms | 8960 KB |
1_07.txt | AC | 11 ms | 8832 KB |
1_08.txt | AC | 23 ms | 8832 KB |
1_09.txt | AC | 23 ms | 8832 KB |
1_10.txt | AC | 10 ms | 8704 KB |
1_11.txt | AC | 23 ms | 8832 KB |
1_12.txt | AC | 9 ms | 8576 KB |
1_13.txt | AC | 23 ms | 8960 KB |
1_14.txt | AC | 10 ms | 8832 KB |
1_15.txt | AC | 11 ms | 8960 KB |
1_16.txt | AC | 11 ms | 8832 KB |
1_17.txt | AC | 11 ms | 8960 KB |
1_18.txt | AC | 10 ms | 8832 KB |
1_19.txt | AC | 10 ms | 8832 KB |
1_20.txt | AC | 22 ms | 8832 KB |
1_21.txt | AC | 10 ms | 8960 KB |
1_22.txt | AC | 10 ms | 8832 KB |
1_23.txt | AC | 10 ms | 8832 KB |
1_24.txt | AC | 10 ms | 8832 KB |
1_25.txt | AC | 10 ms | 8960 KB |
1_26.txt | AC | 10 ms | 8704 KB |
1_27.txt | AC | 10 ms | 8832 KB |
1_28.txt | AC | 10 ms | 8832 KB |