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 (x−y)2 dollars. Even if ai=aj(i≠j), 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

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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.

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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.

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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.

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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.

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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

#include <iostream>
#include <algorithm>
#include <cstring>
#include <cstdio>
#include <vector>
#include <cstdlib>
#include <iomanip>
#include <cmath>
#include <ctime>
#include <map>
#include <set>
#include <queue>
#include <stack>
using namespace std;
#define lowbit(x) (x&(-x))
#define max(x,y) (x>y?x:y)
#define min(x,y) (x<y?x:y)
#define MAX 100000000000000000
#define MOD 1000000007
#define pi acos(-1.0)
#define ei exp(1)
#define PI 3.141592653589793238462
#define INF 0x3f3f3f3f3f
#define mem(a) (memset(a,0,sizeof(a)))
typedef long long ll;
ll gcd(ll a,ll b){
    return b?gcd(b,a%b):a;
}
bool cmp(int x,int y)
{
    return x>y;
}
const int N=10005;
const int mod=1e9+7;
int a[101];
int main()
{
    std::ios::sync_with_stdio(false);
    int n;
    while(cin>>n){
        int s=0;
        for(int i=0;i<n;i++)
            cin>>a[i];
        sort(a,a+n);
        if(a[0]==a[n-1]) cout<<s<<endl;
        else{
            s=1234567;
            int t=0,j;
            for(int i=a[0];i<a[n-1];i++){
                t=0;
                for(j=0;j<n;j++){
                    t+=(i-a[j])*(i-a[j]);
                }
                if(t<s) s=t;
            }
            cout<<s<<endl;
        }
    }
    return 0;
}