三分模板

double solve(double MIN,double MAX){    double Left, Right;    double mid, midmid;    double mid_value, midmid_value;    Left = MIN;    Right = MAX;    while (Left +eps < Right)    {        mid = (Left + Right) / 2;        midmid = (mid + Right) / 2;        mid_value = Calc(mid);        midmid_value = Calc(midmid);        ///求最大值改成>= 最小值改成<=        if (mid_value >= midmid_value) Right = midmid;        else Left = mid;    }    return Left;}

三分法可以求解有在区间内有单峰极值的函数，Calc是要进行三分法的函数，MIN和MAX是区间的左界和右界，也就是范围了。