模拟退火2 P3878 [TJOI2010]分金币

 1 #include<bits/stdc++.h>
 2 using namespace std;
 3 typedef long long ll;
 4 ll ans,n,sum;
 5 int a[100];
 6 
 7 int f()
 8 {
 9     int t=0;
10     for(int i=1;i<=n/2;i++)t+=a[i];
11     return abs(sum-2*t);
12 }
13 void mnth()
14 {
15     for(double T=5000;T>1e-15;T*=0.945)
16     {
17         int x1=rand()%n+1;
18         int x2=rand()%n+1;
19         swap(a[x1],a[x2]);
20         int nowsum=f();
21         if(nowsum<ans)ans=nowsum;
22         else if(exp((ans-nowsum)/T)*RAND_MAX<rand())swap(a[x1],a[x2]);
23     }
24 }
25 int main()
26 {
27     ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
28     int T;
29     cin>>T;
30     while(T--)
31     {
32         ans=INT_MAX,sum=0;
33         cin>>n;
34         for(int i=1;i<=n;i++)cin>>a[i],sum+=a[i];
35         int x=1000;
36         while(x--)mnth();
37         cout<<ans<<endl;
38     }
39     return 0;
40 }

标签：rand,nowsum,int,sum,P3878,模拟退火,ans,TJOI2010,ll
来源： https://www.cnblogs.com/matt-su/p/16096311.html