#include <iostream>
#include <list>
using namespace std;

/*
        Value类:
        用来存储一个区间的左边界值和右边界值
*/
class Value {
    private:
        double leftBound;
        double rightBound;
    public:
        double getLeftBound() {
            return leftBound;
        }
        void setLeftBound(double leftBound) {
            this->leftBound = leftBound;
        }
        double getRightBound() {
            return rightBound;
        }
        void setRightBound(double rightBound) {
            this->rightBound = rightBound;
        }
};

/*
    Array类：
    利用list类库作为模式定义一个存储容器来存储结果
*/
typedef list<Value> Array;

/*
    f(x)=0这个函数的逻辑实现
*/
double f(double x) {
    return x*x-5*x+6;
}

/*
    等步长扫描法实现：
        SameStepScan方法：
        参数：
            left：左边界
            right：右边界
            stepLength：步长值
                    array: 结果集
*/
void SameStepScan(double left, double right, double stepLength, Array *array) {
    double x0 = left;
    double x1 = x0 + stepLength;
    while(x1 <= right) {
        if(f(x0)*f(x1)<0) {
            Value value;
            value.setLeftBound(x0);
            value.setRightBound (x1);
            (*array).push_back(value);
        }
        x0 = x1;
        x1 = x0 + stepLength;
    }
}

/*
    main方法测试
*/
int main() {
    Array *array = new Array();
    SameStepScan(1, 10, 0.3, array);
    for(Array::iterator it = (*array).begin(); it != (*array).end(); it++) {
        cout<<"("<<(*it).getLeftBound()<<", "<<(*it).getRightBound()<<")"<<endl;
    }
    return 0;
}

/*
    二分法实现：
    BinaryDivide：
    left：左边界
    right：右边界
    accuracy：精度控制量
    value：近似值
*/
void BinaryDivide(double left, double right, double accuracy, double &value) {
    double a1 = left;
    double b1 = right;
    double x = (a1+b1)/2;
    while(b1-a1 > accuracy) {
        if(f(a1)*f(x) < 0) {
            b1 = x;
            x = (a1+b1)/2;
        } else {
            a1 = x;
            x = (a1+b1)/2;
        }
    }
    value = x;
}

/*
    main方法测试
*/
int main() {
    double value;
    Array *array = new Array();
    SameStepScan(1, 10, 0.3, array);
    for(Array::iterator it = (*array).begin(); it != (*array).end(); it++) {
        cout<<"("<<(*it).getLeftBound()<<", "<<(*it).getRightBound()<<")"<<endl;
        BinaryDivide((*it).getLeftBound(), (*it).getRightBound(), 0.00001, value);
        cout<<"value : "<<value<<endl;
    }
    return 0;
}