NC 14545 DFS + DP

题意

传送门 NC 14545

题解

D F S DFS DFS 求节点 1 1 1 的所有连通节点， D P DP DP 求解背包问题。

#include <bits/stdc++.h>
using namespace std;
#define maxn 10005
#define maxc 505
typedef long long ll;
int N, M, C, a[maxn], b[maxn], used[maxn], dp[maxc];
vector<int> G[maxn], net;

void dfs(int u)
{
    net.push_back(u);
    used[u] = 1;
    for (int i = 0; i < G[u].size(); i++)
    {
        int v = G[u][i];
        if (!used[v])
            dfs(v);
    }
}

int main()
{
    int t;
    scanf("%d", &t);
    while (t--)
    {
        scanf("%d%d%d", &N, &M, &C);
        G[1].clear();
        for (int i = 2; i <= N; i++)
        {
            scanf("%d%d", a + i, b + i);
            G[i].clear();
        }
        for (int i = 0; i < M; i++)
        {
            int x, y;
            scanf("%d%d", &x, &y);
            G[x].push_back(y);
            G[y].push_back(x);
        }
        net.clear();
        memset(used, 0, sizeof(used));
        memset(dp, 0, sizeof(dp));
        dfs(1);
        for (int i = 0; i < net.size(); i++)
        {
            int id = net[i];
            for (int j = C; j >= a[id]; j--)
            {
                dp[j] = max(dp[j], dp[j - a[id]] + b[id]);
            }
        }
        printf("%d\n", *max_element(dp, dp + C + 1));
    }
    return 0;
}