可以把vector替换为数组重写一遍吗
时间: 2024-02-17 11:04:59 浏览: 26
当然,以下是用数组实现的代码:
```c++
#include <iostream>
#include <cmath>
using namespace std;
//定义预测模型类
class TimeSeriesForecast {
private:
int n; //预测所需的前n天数据
double* data; //输入的时间序列数据
double alpha; //平滑系数
double beta; //趋势系数
double* forecasts; //存储预测结果的数组
public:
TimeSeriesForecast(int n, double alpha, double beta) {
this->n = n;
this->alpha = alpha;
this->beta = beta;
this->data = new double[n + 1];
this->forecasts = new double[n + 1];
}
//添加新数据
void addData(double d[], int size) {
for (int i = 0; i < size; i++) {
data[i] = d[i];
}
}
//计算预测值
void forecast() {
double a = data[0]; //初始值
double b = 0; //初始趋势
double s = data[0]; //初始季节性组件
double phi = 0; //初始季节性指数
double y = 0; //预测值
//计算初始趋势
for (int i = 0; i < n; i++) {
b += (data[i + 1] - data[i]);
}
b /= n;
//计算初始季节性指数
double* seasonal_indices = new double[n];
for (int i = 0; i < n; i++) {
seasonal_indices[i] = data[i] / s;
}
for (int i = 0; i < n; i++) {
phi += seasonal_indices[i];
}
phi /= n;
//预测
for (int i = 0; i < n + 1; i++) {
if (i == 0) {
y = data[0];
} else if (i <= n) {
//计算初始值
y = alpha * data[i] + (1 - alpha) * (a + b);
//计算初始趋势
b = beta * (y - a) + (1 - beta) * b;
//计算初始季节性组件
s = alpha * data[i] / phi + (1 - alpha) * s;
//计算初始季节性指数
phi = beta * (data[i] / s) + (1 - beta) * phi;
} else {
//计算预测值
double temp = y;
y = alpha * temp + (1 - alpha) * (a + b);
b = beta * (y - a) + (1 - beta) * b;
s = alpha * temp / phi + (1 - alpha) * s;
phi = beta * (temp / s) + (1 - beta) * phi;
}
forecasts[i] = y;
}
delete[] seasonal_indices;
}
//输出预测结果
void printForecasts() {
for (int i = 0; i < n + 1; i++) {
cout << "Day " << i << " forecast: " << round(forecasts[i]) << endl;
}
}
~TimeSeriesForecast() {
delete[] data;
delete[] forecasts;
}
};
int main() {
//初始化预测模型
int n = 5;
double alpha = 0.5;
double beta = 0.2;
TimeSeriesForecast forecast(n, alpha, beta);
//添加时间序列数据
double d[] = {100, 120, 110, 130, 125, 135, 140, 150, 145, 155};
forecast.addData(d, 10);
//计算预测值并输出结果
forecast.forecast();
forecast.printForecasts();
return 0;
}
```
这个代码与之前的代码的逻辑相同,只是将vector替换为了数组。特别地,为了方便,我们使用了动态内存分配。需要注意的是,由于我们使用了动态内存分配,因此需要在析构函数中释放内存。