题解

#include<bits/stdc++.h>
using namespace std;
int m,n,k,b[100001],c[100001],anss,ans,maxn,maxk=1e9,ti[100001];
pair<int,int>a[100001];
int main(){
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	cin >> m >> n >> k;
	for(int i = 1;i <= n;i++){
		cin >> a[i].second;
		ti[a[i].second]++;
	}
    for(int i = 1;i <= n;i++){
		cin >> a[i].first;
	}
    sort(a + 1,a + n + 1);
	for(int i = n;i >= 1;i--){
		if(b[a[i].second] < k){
			b[a[i].second] += a[i].first; 
			if(b[a[i].second] >= k){
                anss++; 
            }
			ans++;
			c[a[i].second]++; 
			if(maxn < c[a[i].second]){
                maxn = c[a[i].second],maxk = ti[a[i].second];
            }else if(maxn == c[a[i].second]){
                maxk = min(ti[a[i].second],maxk);
            }
		}
	}if(anss != m || maxn * 2 - 1 > n || maxn > n - maxk){
        cout<<"-1";
    }else{
        cout << max(maxn * 2 - 1,ans);
    }
	return 0;
}