《 Skynet 游戏服务器开发实战》

//追赶法解方程组Pursue.cpp
#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;


class SolutionEquations
{
private:
    vector<double> a;
    vector<double> b;
    vector<double> c;
    vector<double> f;
    vector<double> x;
    
public:
    void setABCF(vector<double> in_a, vector<double> in_b, vector<double> in_c, vector<double> in_f)
    {
        a = in_a;
        b = in_b;
        c = in_c;
        f = in_f;
    }
    //追赶法解方程组
    vector<double>& Pursue()
    {
        vector<double> bita;
        vector<double> y;
        int n = f.size();
        bita.push_back(c.at(0)/b.at(0));
        y.push_back(f.at(0)/b.at(0));
        for (int i=1; i<n-1; i++)
        {
            double alpha = b.at(i)-a.at(i)*bita.at(i-1);
            double tmp = c.at(i)/alpha;
            bita.push_back(tmp);
            tmp = (f.at(i)-a.at(i)*y.at(i-1))/alpha;
            y.push_back(tmp);
        }
        double alpha = b.at(n-1)-a.at(n-1)*bita.at(n-2);
        double tmp = (f.at(n-1)-a.at(n-1)*y.at(n-2))/alpha;
        y.push_back(tmp);

        x.push_back(y.at(n-1));
        for (int i=n-2,k=0; i>=0; i--,k++)
        {
            double tmp = y.at(i)-bita.at(i)*x.at(k);
            x.push_back(tmp);
        }
        reverse(x.begin(),x.end());
        return x;
    }
};

int main()
{
    SolutionEquations solution;
    vector<double> a;
    vector<double> b;
    vector<double> c;
    vector<double> f;

    a.push_back(0);
    a.push_back(-1);
    a.push_back(-2);
    a.push_back(-3);
    b.push_back(2);
    b.push_back(3);
    b.push_back(4);
    b.push_back(5);
    c.push_back(-1);
    c.push_back(-2);
    c.push_back(-3);
    f.push_back(6);
    f.push_back(1);
    f.push_back(-2);
    f.push_back(1);
    
    solution.setABCF(a,b,c,f);
        
    vector<double>x = solution.Pursue();
    
    for (int i=0; i<x.size(); i++)
    {
        cout << "x=" << x.at(i) << endl;
    }
    
}