AcWing 487. 金明的预算方案（dp+dp 预处理）

代码

#include <bits/stdc++.h>
using namespace std;
#define db  double
#define ll  long long
#define Pir pair<int, int>
#define fi  first
#define se  second
#define pb  push_back
#define m_p make_pair
#define inf 0x3f3f3f3f
#define INF 0x3f3f3f3f3f3f3f3f
/*==========ACMer===========*/
const int N = 42005;
int f[65][N];
struct Node
{
    
    
    int v, w;
} fa[65];
vector<Node> son[65];
int n, m;


int main()
{
    
    
    scanf("%d %d", &m, &n);
    m /= 10;
    int a, b, c;
    for (int i = 1; i <= n; i ++) {
    
    
        scanf("%d %d %d", &a, &b, &c);
        if (c == 0) 
            fa[i] = Node{
    
     a / 10, a * b };
        else 
            son[c].pb(Node{
    
     a / 10, a * b });
    }

    for (int i = 1; i <= n; i ++) {
    
    
        if (fa[i].v) {
    
    
            for (int j = fa[i].v; j <= m; j ++ )
                f[i][j] = f[i - 1][j - fa[i].v] + fa[i].w;

            for (auto x : son[i]) {
    
    
                for (int j = m; j >= x.v; j --) {
    
    
                    if (f[i][j - x.v] > 0) {
    
    
                        f[i][j] = max(f[i][j], f[i][j - x.v] + x.w);
                    }
                }
            }
        }

        for (int j = 0; j <= m; j ++)
            f[i][j] = max(f[i][j], f[i - 1][j]);
    }

    printf("%d\n", f[n][m]);

    return 0;
}