贪心/二分——cf1342D

直接判断分成x组能否满足，从大到小平均分是最合理的方案

 #include<bits/stdc++.h>
using namespace std;
#define N 200006
 
int suf[N],n,k,m[N],c[N];
vector<int>v[N];
 
long long t[N]; 
int judge(int x){ //分成x组 
    for(int i=1;i<=k;i++)t[i]=1ll*c[i]*x;
    for(int i=1;i<=k;i++)
        if(suf[i]>t[i])return 0;
    return 1;
}
 
int main(){
    cin>>n>>k;
    for(int i=1;i<=n;i++)scanf("%d",&m[i]);
    sort(m+1,m+1+n);
    for(int i=1;i<=n;i++)suf[m[i]]++;
    for(int i=k;i>=1;i--)suf[i]+=suf[i+1];
    
    for(int i=1;i<=k;i++)scanf("%d",&c[i]);
    int L=1,R=n,mid,ans;
    while(L<=R){
        mid=L+R>>1;
        if(judge(mid))
            R=mid-1,ans=mid;
        else L=mid+1;
    }
    
    int p=1;
    for(int i=1;i<=n;i++){
        v[p].push_back(m[i]);
        p++;if(p>ans)p-=ans;
    }
    cout<<ans<<"\n";
    for(int i=1;i<=ans;i++){
        cout<<v[i].size()<<' ';
        for(auto x:v[i])cout<<x<<" ";
        puts("");
    }
    
}