mirror of
https://github.com/Kiritow/OJ-Problems-Source.git
synced 2024-03-22 13:11:29 +08:00
94 lines
2.1 KiB
C++
94 lines
2.1 KiB
C++
#include<cstdio>
|
|
#include<cstring>
|
|
#include<algorithm>
|
|
using namespace std;
|
|
#define min(a,b) a>b?b:a
|
|
#pragma comment(linker,"/STACK:1000000000,1000000000")
|
|
const int maxn = 10010;
|
|
const int INF = 1000000000;
|
|
int dp[maxn][110];
|
|
int sum[maxn],sumd[maxn];
|
|
int head[maxn];
|
|
struct Edge{
|
|
int v,next;
|
|
}edge[2*maxn];int N,L,E;
|
|
void add_edge(int a,int b)
|
|
{
|
|
edge[E].v=b;
|
|
edge[E].next=head[a];
|
|
head[a]=E++;
|
|
}
|
|
void dfs(int u,int fa)
|
|
{
|
|
int i,j,k,v;
|
|
sum[u]=1;sumd[u]=0;
|
|
fill(dp[u],dp[u]+L+1,INF);
|
|
for(i=head[u];i!=-1;i=edge[i].next)
|
|
{
|
|
v=edge[i].v;
|
|
if(v==fa) continue;
|
|
dfs(v,u);
|
|
sumd[u]+=sumd[v]+sum[v];
|
|
sum[u]+=sum[v];
|
|
}
|
|
dp[u][0]=sumd[u];
|
|
for(i=head[u];i!=-1;i=edge[i].next)
|
|
{
|
|
v=edge[i].v;
|
|
if(v==fa) continue;
|
|
for(j=1;j<=L;j++)
|
|
dp[u][j]=min(dp[u][j],dp[v][j-1]+sumd[u]-sumd[v]-sum[v]);
|
|
}
|
|
}
|
|
int ans[maxn];
|
|
void solve(int u,int fa)
|
|
{
|
|
int i,a,v;
|
|
if(u==0) ans[u]=sumd[0];
|
|
else ans[u]=N-sum[u]+sumd[fa]-sum[u];
|
|
int tmp[110];
|
|
fill(tmp,tmp+L+1,INF);
|
|
int mi=INF;
|
|
for( i=head[u];i!=-1;i=edge[i].next)
|
|
{
|
|
v=edge[i].v;
|
|
if(v==fa) continue;
|
|
for( a=0;a<=L-2;a++)
|
|
mi=min(mi,tmp[L-2-a]+dp[v][a]-sumd[v]-sum[v]);
|
|
for( a=0;a<=L-1;a++)
|
|
{
|
|
tmp[a]=min(tmp[a],dp[v][a]-sumd[v]-sum[v]);
|
|
if(a) tmp[a]=min(tmp[a],tmp[a-1]);
|
|
}
|
|
}
|
|
mi=min(mi,tmp[L-1]);
|
|
sumd[u]=ans[u];
|
|
ans[u]+=mi;
|
|
for(i=head[u];i!=-1;i=edge[i].next)
|
|
{
|
|
v=edge[i].v;
|
|
if(v==fa) continue;
|
|
solve(v,u);
|
|
}
|
|
}
|
|
int main()
|
|
{
|
|
int i,j,k,a,b;
|
|
while(scanf("%d%d",&N,&L),(N||L))
|
|
{
|
|
if(N==1) {puts("0");continue;}
|
|
E=0;
|
|
memset(head,-1,sizeof(head));
|
|
for(i=0;i<N-1;i++)
|
|
{
|
|
scanf("%d%d",&a,&b);
|
|
add_edge(a,b);
|
|
add_edge(b,a);
|
|
}
|
|
dfs(0,0);
|
|
solve(0,0);
|
|
printf("%d\n",*min_element(ans,ans+N));
|
|
}
|
|
return 0;
|
|
}
|