B. Yet Another Array Partitioning Task

http://codeforces.com/contest/1114/problem/B

题意：给n,m,k(2~2e5),和n个数的a数组，把a数组分成k部分（至少m个数），每部分取m个最大的数，求sum最大，输出每段下标；

思路：找出不需要的n-m*k个数，再把其他数每m个分组；

#include<algorithm>
#include<set>
#include<vector>
#include<queue>
#include<cmath>
#include<cstring>
#include<iostream>
#include<algorithm>
#include<set>
#include<vector>
#include<queue>
#include<cmath>
#include<cstring>
#include<sstream>
#include<cstdio>
#include<ctime>
#include<map>
#include<stack>
#include<string>
using namespace std;

#define sfi(i) scanf("%d",&i)
#define pri(i) printf("%d\n",i)
#define sff(i) scanf("%lf",&i)
#define ll long long
#define mem(x,y) memset(x,y,sizeof(x))
#define INF 0x3f3f3f3f
#define eps 1e-6
#define PI acos(-1)
#define lowbit(x) ((x)&(-x))
#define fl() printf("flag\n")
ll gcd(ll a,ll b){while(b^=a^=b^=a%=b);return a;}
const int maxn=2e5+9;
const int mod=1e9+7;

template <class T>
inline void sc(T &ret)
{
    char c;
    ret = 0;
    while ((c = getchar()) < '0' || c > '9');
    while (c >= '0' && c <= '9')
    {
        ret = ret * 10 + (c - '0'), c = getchar();
    }
}


int ans[maxn];
int a[maxn];
ll sum;
int b[maxn];
bool vis[maxn];
map<int,int>mp;
int main()
{
    int n,m,k;
    cin>>n>>m>>k;
    for(int i=0;i<n;i++)
    {
        cin>>a[i];
        b[i]=a[i];
        sum+=a[i];
    }
    for(int i=0;i<=n;i++)
    {
        vis[i]=1;
    }
    sort(b,b+n);
    int num=0;
    for(int i=0;i<n-m*k;i++)
    {
        mp[b[i]]++;
        sum-=b[i];
    }
    for(int i=0;i<n;i++)
    {
        if(mp[a[i]]>0)
        {
            //cout<<a[i]<<endl;
            vis[i]=0;
            mp[a[i]]--;
        }
    }
    cout<<sum<<endl;
    int cnt=0;
    for(int i=0;i<n;i++)
    {
        //cout<<vis[i]<<" ";
        num+=vis[i];
        if(num%m==0&&vis[i]) cout<<i+1<<" ",cnt++;
        if(cnt==k-1) break;
    }
    return 0;
}