codeforces #339 div2 D

http://codeforces.com/contest/613/problem/B 题意:有n个技能,初始每个技能的level为a[i],每个技能最大level为A(不妨称为满级技能),设满级技能个数为maxnum,最小的技能level为minval,问如何将m个技能点分配到n个技能上使得cfmaxsum+cmminval (n<=1E5,a[i],A<=1E9,cf,cm<=1E3,m<=1E15)

思路:贪心。如果让有限的maxsum个技能满级的话,那么一定是让初始最大的maxsum技能满级更优。我们O(n)可以预处理一个c[i]数组,表示将i个技能变成最大值的最小花费。

然后再预处理一个前缀和数组,sum[i]表示初始最小的i个的技能的花费之和。

然后从0到n枚举变成最大值的技能的个数,在剩下的技能中二分能达到的最小值。

注意要按照原来顺序输出,所以记得记录id.

  1/* ***********************************************
  2Author :111qqz
  3Created Time :2016年02月20日 星期六 13时11分30秒
  4File Name :code/cf/#339/D.cpp
  5************************************************ */
  6
  7#include <cstdio>
  8#include <cstring>
  9#include <iostream>
 10#include <algorithm>
 11#include <vector>
 12#include <queue>
 13#include <set>
 14#include <map>
 15#include <string>
 16#include <cmath>
 17#include <cstdlib>
 18#include <ctime>
 19#define fst first
 20#define sec second
 21#define lson l,m,rt<<1
 22#define rson m+1,r,rt<<1|1
 23#define ms(a,x) memset(a,x,sizeof(a))
 24typedef long long LL;
 25#define pi pair < int ,int >
 26#define MP make_pair
 27
 28using namespace std;
 29const double eps = 1E-8;
 30const int dx4[4]={1,0,0,-1};
 31const int dy4[4]={0,-1,1,0};
 32const int inf = 0x3f3f3f3f;
 33const int N=1E5+7;
 34LL n,A,cf,cm,m;
 35LL b[N];
 36LL c[N]; //c[i]表示将i个变为最大值需要的最少花费
 37LL sum[N] ; //sum[i]表示花费最少的i个的价值和
 38struct node
 39{
 40    LL val;
 41    int id;
 42
 43    bool operator < (node b)const
 44    {
 45	return val>b.val;
 46    }
 47}a[N];
 48
 49bool cmp (LL a,LL b)
 50{
 51    return a<b;
 52}
 53bool cmp2( node a,node b)
 54{
 55    return a.id<b.id;
 56}
 57int main()
 58{
 59	#ifndef  ONLINE_JUDGE 
 60	freopen("code/in.txt","r",stdin);
 61  #endif
 62	ios::sync_with_stdio(false);
 63	cin>>n>>A>>cf>>cm>>m;
 64	for ( int i = 1 ; i <= n ; i++) cin>>a[i].val,a[i].id =  i,b[i] = a[i].val;
 65	sort(b+1,b+n+1,cmp);
 66	sort(a+1,a+n+1);
 67
 68	LL cost = 0 ;
 69	c[0] = 0;
 70	for ( int i = 1 ; i <= n ; i++)
 71	{
 72	    cost +=A-a[i].val;
 73	    c[i] = cost;
 74	}
 75	sum[0] = 0LL;
 76	for ( int i = 1 ; i <= n ; i++) sum[i] = sum[i-1] + b[i];
 77
 78	LL maxnum;
 79	LL minval;
 80	LL ans = -1;
 81	for ( int i = 0 ; i <= n ; i++) //i表示达到最大值的有i个
 82	{
 83	    LL M = m;
 84	    LL left = M - c[i];
 85	    if (left<0) break;
 86
 87	    LL l=0,r=A;
 88
 89	    while (l<r) //在剩下的n-i个数里二分最小值
 90	    {
 91		LL mid = (l+r+1)>>1;
 92		int x= lower_bound(b+1,b+n-i+1,mid)-b-1;
 93		if (mid*x-sum[x]<=left) l = mid;
 94		else r = mid -1;
 95	    }
 96
 97	    if (cf*i+cm*l>ans)
 98	    {
 99		ans = cf*i+cm*l;
100		maxnum  = i;
101		minval = l;
102	    }
103	}
104
105	for ( int i = 1 ; i <= maxnum ; i++) a[i].val = A;
106	for ( int i = 1 ; i <= n ; i++) if (a[i].val<minval) a[i].val = minval;
107	sort(a+1,a+n+1,cmp2);
108	cout<<ans<<endl;
109	for ( int i = 1 ; i <= n-1 ; i++) cout<<a[i].val<<" ";
110	cout<<a[n].val<<endl;
111
112  #ifndef ONLINE_JUDGE  
113  fclose(stdin);
114  #endif
115    return 0;
116}