洛谷 P2623 物品选取

题目传送门

解题思路:

就是一个比较奇特的混合背包,每种情况单独处理就好了

AC代码:

#include<iostream>
#include<cstdio>

using namespace std;

int n,m,w[101],c[101],a[101],id[101],f[2001]; 

int main() {
    scanf("%d%d",&n,&m);
    for(int i = 1;i <= n; i++) {
        scanf("%d",&id[i]);
        if(id[i] == 1)
            scanf("%d%d",&w[i],&c[i]);
        if(id[i] == 2)
            scanf("%d%d%d",&c[i],&w[i],&a[i]);
        if(id[i] == 3)
            scanf("%d%d",&c[i],&w[i]);
    }
    for(int i = 1;i <= n; i++) {
        if(id[i] == 1)
            for(int j = m;j >= 0; j--)
                for(int k = j;k >= 0; k--)
                    f[j] = max(f[j],f[k] + w[i] * (j - k) * (j - k) - c[i] * (j - k));
        if(id[i] == 2)
            for(int k = 1;k <= a[i]; k++)
                for(int j = m;j >= w[i]; j--)
                    f[j] = max(f[j],f[j-w[i]] + c[i]);
        if(id[i] == 3)
            for(int j = w[i];j <= m; j++)
                f[j] = max(f[j],f[j-w[i]] + c[i]);
    }
    printf("%d",f[m]);
    return 0;
}