いっしょ / Be Together (暴力枚举)

题目链接:http://abc043.contest.atcoder.jp/tasks/arc059_a

Time limit : 2sec / Memory limit : 256MB

Score : 200 points

Problem Statement

Evi has N integers a1,a2,..,aN. His objective is to have N equal integers by transforming some of them.

He may transform each integer at most once. Transforming an integer x into another integer y costs him (xy)2 dollars. Even if ai=aj(ij), he has to pay the cost separately for transforming each of them (See Sample 2).

Find the minimum total cost to achieve his objective.

Constraints

  • 1≦N≦100
  • −100≦ai≦100

Input

The input is given from Standard Input in the following format:

N
a1 a2 ... aN

Output

Print the minimum total cost to achieve Evi's objective.


Sample Input 1

Copy
2
4 8

Sample Output 1

Copy
8

Transforming the both into 6s will cost (4−6)2+(8−6)2=8 dollars, which is the minimum.


Sample Input 2

Copy
3
1 1 3

Sample Output 2

Copy
3

Transforming the all into 2s will cost (1−2)2+(1−2)2+(3−2)2=3 dollars. Note that Evi has to pay (1−2)2 dollar separately for transforming each of the two 1s.


Sample Input 3

Copy
3
4 2 5

Sample Output 3

Copy
5

Leaving the 4 as it is and transforming the 2 and the 5 into 4s will achieve the total cost of (2−4)2+(5−4)2=5 dollars, which is the minimum.


Sample Input 4

Copy
4
-100 -100 -100 -100

Sample Output 4

Copy
0

Without transforming anything, Evi's objective is already achieved. Thus, the necessary cost is 0.

题解:数据不大 枚举

 1 #include <iostream>
 2 #include <algorithm>
 3 #include <cstring>
 4 #include <cstdio>
 5 #include <vector>
 6 #include <cstdlib>
 7 #include <iomanip>
 8 #include <cmath>
 9 #include <ctime>
10 #include <map>
11 #include <set>
12 #include <queue>
13 #include <stack>
14 using namespace std;
15 #define lowbit(x) (x&(-x))
16 #define max(x,y) (x>y?x:y)
17 #define min(x,y) (x<y?x:y)
18 #define MAX 100000000000000000
19 #define MOD 1000000007
20 #define pi acos(-1.0)
21 #define ei exp(1)
22 #define PI 3.141592653589793238462
23 #define INF 0x3f3f3f3f3f
24 #define mem(a) (memset(a,0,sizeof(a)))
25 typedef long long ll;
26 ll gcd(ll a,ll b){
27     return b?gcd(b,a%b):a;
28 }
29 bool cmp(int x,int y)
30 {
31     return x>y;
32 }
33 const int N=10005;
34 const int mod=1e9+7;
35 int a[101];
36 int main()
37 {
38     std::ios::sync_with_stdio(false);
39     int n;
40     while(cin>>n){
41         int s=0;
42         for(int i=0;i<n;i++)
43             cin>>a[i];
44         sort(a,a+n);
45         if(a[0]==a[n-1]) cout<<s<<endl;
46         else{
47             s=1234567;
48             int t=0,j;
49             for(int i=a[0];i<a[n-1];i++){
50                 t=0;
51                 for(j=0;j<n;j++){
52                     t+=(i-a[j])*(i-a[j]);
53                 }
54                 if(t<s) s=t;
55             }
56             cout<<s<<endl;
57         }
58     }
59     return 0;
60 }
posted @ 2017-08-04 23:55  wydxry  阅读(356)  评论(0编辑  收藏  举报
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