【模拟退火】【爬山算法】模板

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题目链接
玄学算法。。。一开始不知道调参wa到怀疑人生
后来尝试改一下delta竟然过了。。。退火和爬山的区别其实就是当没有更优解的时候退火会以一个概率来接收，爬山就不接受。所以把else if(exp((res-temp)/t)*RAND_MAX > rand())注释掉就是爬山了。。

#pragma GCC optimize(2)
#include<algorithm>
#include<iostream>
#include<cstdio>
#include<cmath>
using namespace std;
#define ft first
#define sd second
#define all(c) ((c).begin()), ((c).end())
#define mp(a, b) make_pair(a, b)
#define pb(x) push_back(x)
const int maxn = 1e5+5;
typedef long long ll;
const ll mod = 1e9+7;
int Case = 1;
int n, m;
struct node{
    double x, y, z;
}cc[maxn];
double res, t;
const double delta = 0.993;
double resx, resy;
double cal(double X, double Y) {
    double rt = 0;
    for(int i = 1; i <= n; i++) {
        double deltax = X-cc[i].x, deltay = Y-cc[i].y;
        rt  += sqrt(deltax*deltax+deltay*deltay)*cc[i].z;
    }
    return rt;
}
void simulate_anneal() {
    t = 2000;
    double x = resx, y = resy;
    while(t > 1e-14) {
        double X = x + ((rand()<<1)-RAND_MAX)*t;
        double Y = y + ((rand()<<1)-RAND_MAX)*t;
        double temp = cal(X, Y);
        if(temp < res) {
            res = temp;
            resx = X;resy = Y;
            x = X;y = Y;
        }
        //else if(exp((res-temp)/t)*RAND_MAX > rand())x = X, y = Y;
        t *= delta;
    }
}
void solve() {
    cin>>n;res = 1e18;
    resx = 0, resy = 0;
    for(int i = 1; i <= n; i++)
        {cin>>cc[i].x>>cc[i].y>>cc[i].z; resx += cc[i].x; resy += cc[i].y;}
    resx /= n;resy /= n;
    simulate_anneal();
    simulate_anneal();
    simulate_anneal();
    printf("%.3f %.3f\n", resx, resy);
    return;
}
int main() {
    srand(19260817);
    ios::sync_with_stdio(false);cin.tie(0);std::cout.tie(0);
#ifndef ONLINE_JUDGE
    freopen("in.txt", "r", stdin);
    //freopen("out.txt","w",stdout);
#endif
    //scanf("%d", &Case);
    while(Case--){
        solve();
    }
    return 0;
}