OI WIKI上的模拟退火

#include <cmath>
#include <cstdlib>
#include <ctime>
#include <iomanip>
#include <iostream>constexpr int N = 10005;
int n, x[N], y[N], w[N];
double ansx, ansy, dis;double Rand() { return (double)rand() / RAND_MAX; }double calc(double xx, double yy) {double res = 0;for (int i = 1; i <= n; ++i) {double dx = x[i] - xx, dy = y[i] - yy;res += sqrt(dx * dx + dy * dy) * w[i];}if (res < dis) dis = res, ansx = xx, ansy = yy;return res;
}void simulateAnneal() {double t = 100000;double nowx = ansx, nowy = ansy;while (t > 0.001) {double nxtx = nowx + t * (Rand() * 2 - 1);double nxty = nowy + t * (Rand() * 2 - 1);double delta = calc(nxtx, nxty) - calc(nowx, nowy);if (exp(-delta / t) > Rand()) nowx = nxtx, nowy = nxty;t *= 0.97;}for (int i = 1; i <= 1000; ++i) {double nxtx = ansx + t * (Rand() * 2 - 1);double nxty = ansy + t * (Rand() * 2 - 1);calc(nxtx, nxty);}
}int main() {std::cin.tie(nullptr)->sync_with_stdio(false);srand(0);  // 注意，在实际使用中，不应使用固定的随机种子。std::cin >> n;for (int i = 1; i <= n; ++i) {std::cin >> x[i] >> y[i] >> w[i];ansx += x[i], ansy += y[i];}ansx /= n, ansy /= n, dis = calc(ansx, ansy);simulateAnneal();std::cout << std::fixed << std::setprecision(3) << ansx << ' ' << ansy<< '\n';return 0;
}