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| #include <iostream>
#include <algorithm>
#include <cstring>
#include <cstdio>
using namespace std;
const int maxn = 305;
struct edge
{
int to, nxt, v;
}e[maxn << 1];
int f[maxn][maxn], g[maxn][maxn], h[maxn][maxn];
int n, lnk[maxn], ptr, T, ans;
int t[maxn], w[maxn];
inline void add(int bgn, int end, int val)
{
e[++ptr] = (edge){end, lnk[bgn], val};
lnk[bgn] = ptr;
}
void dfs(int i, int fa)
{
int cf[maxn], cg[maxn], ch[maxn];
for(int j = t[i]; j <= T; ++j)
f[i][j] = w[i],
g[i][j] = w[i],
h[i][j] = w[i];
for(int p = lnk[i]; p; p = e[p].nxt)
{
int y = e[p].to;
if(y == fa) continue;
dfs(y, i);
for(int j = 0; j <= T; ++j)
cf[j] = f[i][j], cg[j] = g[i][j], ch[j] = h[i][j];
for(int j = 0; j <= T; ++j)
{
for(int k = 0; k <= T; ++k)
{
if(j - k - 2 * e[p].v >= 0)
h[i][j] = max(h[i][j], ch[j - k - 2 * e[p].v] + f[y][k]),
h[i][j] = max(h[i][j], cf[j - k - 2 * e[p].v] + h[y][k]);
if(j - k - e[p].v >= 0)
h[i][j] = max(h[i][j], cg[j - k - e[p].v] + g[y][k]);
}
}
for(int j = T; j >= 0; --j)
{
for(int k = 0; k <= T; ++k)
{
if(j - k - 2 * e[p].v >= 0)
f[i][j] = max(f[i][j], cf[j - k - 2 * e[p].v] + f[y][k]);
}
}
for(int j = T; j >= 0; --j)
{
for(int k = 0; k <= T; ++k)
{
if(j - k - 2 * e[p].v >= 0)
g[i][j] = max(g[i][j], cg[j - k - 2 * e[p].v] + f[y][k]);
}
}
for(int j = T; j >= 0; --j)
{
for(int k = 0; k <= T; ++k)
{
if(j - k - e[p].v >= 0)
g[i][j] = max(g[i][j], cf[j - k - e[p].v] + g[y][k]);
}
}
}
ans = max(max(ans, f[i][T]), max(g[i][T], h[i][T]));
}
int main()
{
freopen("toyuq.in", "r", stdin);
freopen("toyuq.out", "w", stdout);
scanf("%d%d", &n, &T);
for(int i = 1; i <= n; ++i) scanf("%d", &w[i]);
for(int i = 1; i <= n; ++i) scanf("%d", &t[i]);
register int x, y, z;
for(int i = 1; i < n; ++i)
{
scanf("%d%d%d", &x, &y, &z);
add(x, y, z); add(y, x, z);
}
memset(f, 0xcf, sizeof f);
memset(g, 0xcf, sizeof g);
memset(h, 0xcf, sizeof h);
dfs(1, 0);
printf("%d\n", ans);
fclose(stdin);
fclose(stdout);
return 0;
}
|
