直接暴力 限定每種質量物品個數然後求價值前k大的質量

#include<bits/stdc++.h>
using namespace std;
#define N 4005
#define mp(a,b) make_pair(a,b)
#define fi first
#define se second

pair<int,int> p[N];
int n,k,id[N],tot,ed[N],sz[N],c[N],ans,op,ip[N];

bool cmp(int a,int b){return c[ip[a]]>c[ip[b]];}
bool cmp1(int a,int b){return sz[a]>sz[b];}

int main()
{
    freopen("input.txt","r",stdin);
    freopen("output.txt","w",stdout);
    scanf("%d%d",&n,&k);
    for (int i=1,m,c;i<=n;i++) scanf("%d%d",&m,&c),p[i]=mp(m,c);
    sort(p+1,p+n+1);
    for (int i=n;i;i--)
    {
        if (p[i].fi!=p[i+1].fi) ++tot;
        if (p[i-1].fi!=p[i].fi) ed[tot]=i;
        c[tot]+=p[i].se;
        sz[tot]++;
    }
    if (tot<k)
    {
        puts("0 0");
        return 0;
    }
    for (int i=1;i<=tot;i++) ip[i]=i;
    sort(ip+1,ip+tot+1,cmp1);
    for (int i=k;i<=tot;i++)
    {
        if (ans>sz[ip[i]]) break;
        for (int j=1;j<=i;j++) id[j]=j;
        for (int j=1;j<i;j++) while (sz[ip[j]]>sz[ip[i]]) c[ip[j]]-=p[ed[ip[j]]++].se,sz[ip[j]]--;
        sort(id+1,id+i+1,cmp);
        int tmp=0;
        for (int j=1;j<=k;j++) tmp+=c[ip[id[j]]];
        ans=sz[ip[i]];op=max(op,tmp);
    }
    printf("%d %d\n",ans,op);
}