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| #include <cstdio>
#include <algorithm>
using namespace std;
const int N = 160, M = 310;
int n, m, d[N], f[N][N];
int idx, hd[N], nxt[M], edg[M];
void dfs(int x, int fa)
{
f[x][1] = d[x];
for (int i = hd[x]; ~i; i = nxt[i])
{
if (edg[i] == fa)
continue;
dfs(edg[i], x);
for (int j = m; j; j--)
for (int k = 1; k < j; k++)
f[x][j] = min(f[x][j], f[x][k] + f[edg[i]][j - k] - 2);
}
}
void add(int a, int b)
{
nxt[++idx] = hd[a];
hd[a] = idx;
edg[idx] = b;
}
int main()
{
scanf("%d%d", &n, &m);
for (int i = 1; i <= n; i++)
hd[i] = -1;
for (int i = 1, a, b; i < n; i++)
{
scanf("%d%d", &a, &b);
d[a]++, d[b]++;
add(a, b);
add(b, a);
}
for (int i = 1; i <= n; i++)
for (int j = 1; j <= m; j++)
f[i][j] = n;
dfs(1, 0);
int res = n;
for (int i = 1; i <= n; i++)
res = min(res, f[i][m]);
printf("%d", res);
return 0;
}
|