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| #include <bits/stdc++.h>
using namespace std;
const int N = 3001, M = 3000;
int u, x, ww, h[N], w[M], e[M], ne[M], idx;
int n, m, v[N], f[N][N];
void add(int u, int v, int ww) {
e[++idx] = v, w[idx] = ww, ne[idx] = h[u], h[u] = idx;
}
int dfs(int x) {
if (x > n - m) {
f[x][1] = v[x];
return 1;
}
int sum = 0;
for (int i = h[x]; i; i = ne[i]) {
int y = e[i];
int s = dfs(y);
sum += s;
for (int j = sum; j; --j)
for (int k = 1; k <= s; ++k)
if (j >= k) f[x][j] = max(f[x][j], f[x][j - k] + f[y][k] - w[i]);
}
return sum;
}
int main() {
scanf("%d%d", &n, &m);
memset(f, -0x3f3f3f, sizeof f);
register int i = 1;
for (; i <= n - m; ++i) {
scanf("%d", &x);
for (int j = 1; j <= x; ++j) {
scanf("%d%d", &u, &ww);
add(i, u, ww);
}
}
for (; i <= n; ++i) {
scanf("%d", &v[i]);
}
for (i = 1; i <= n; ++i) f[i][0] = 0;
dfs(1);
for (i = m; i; --i)
if (f[1][i] >= 0) {
printf("%d\n", i);
break;
}
return 0;
}
|