目录

模拟退火板子

目录
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#include <bits/stdc++.h>
using namespace std;

int calc() {
  //用dp,最短路,贪心,模拟等算法求出当前解。
}
int SA() {
  double beginT = , endT = , delT = ;
  for (double T = beginT; T > endT; T *= delT) {
    //对于序列,枚举两个数并进行交换,得出当前解
    //对于坐标,随机生成一个点进行计算
    //对于网格图,随机枚举两个格点进行交换
    //...
    if () // 当前解优于最优解
      // 更新最优解
    else if (exp(-当前 / T) * RAND_MAX < rand())  //还原之前的状态
  }
}

int main() {
  srand(rand());
  while((double)clock()/CLOCKS_PER_SEC<=0.8) SA();// 卡时
  return 0;
}

例题

P3878 [TJOI2010] 分金币 程序(傻缺都能看懂)

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#include <bits/stdc++.h>
using namespace std;
const int maxn = 10010;

int n, a[maxn], ans = 0x3f3f3f3f;
int get_diff() {
  int s1 = 0, s2 = 0;
  for (int i = 1; i <= (n + 1) / 2; i++) {
    s1 += a[i];
  }
  for (int i = (n + 1) / 2 + 1; i <= n; i++) {
    s2 += a[i];
  }
  return abs(s1 - s2);
}
void SA(int times) {
  while (times--) {
    double beginT = 10000, endT = 1e-10, delT = 0.95;
    for (double T = beginT; T > endT; T *= delT) {
      int x = rand() % n + 1, y = rand() % n + 1;
      swap(a[x], a[y]);
      int sum = get_diff();
      if (sum < ans)
        ans = sum;
      else {
        if (exp((ans - sum) / T) < (double(rand()) / RAND_MAX))
          swap(a[x], a[y]);
      }
    }
  }
}

int main() {
  srand(rand());
  int T;
  cin >> T;
  while (T--) {
    cin >> n;
    for (int i = 1; i <= n; i++) {
      cin >> a[i];
    }
    SA(1000);
    cout << ans << endl;
    ans = 0x3f3f3f3f;
  }
  return 0;
}