public int gcd(int a, int b)//公约数
        {
            if (a == 0)
            {
                return b;
            }
           else if (b == 0)
            {
                return a;
            }
            else
            {
                return gcd(b % a, a);
            }
        }
        public int Calculate(int type, int op1, int op2)//整数四则运算
        {
            int result = 0;
            if (type == 1)
            {
                result = op1 + op2;
            }
            if (type == 2)
            {
                result = op1 - op2;
            }
            if (type == 3)
            {
                result = op1 * op2;
            }
            if (type == 4)
            {
                result = op1 / op2;
            }
            return result;
        }
        public string CalculateFengsu(int up1, int down1, int up2, int down2, int type)//分数四则运算
        {
            string result = "";
            if (type == 1)
            {
                up1 = (up1 * down2 + up2 * down1);
                down1 = down1 * down2;
                up2 = gcd(up1, down1);
                up1 = up1 / up2;
                down1 = down1 / up2;
                result = up1.ToString() + "/" + down1.ToString();
                return result;
            }
            if (type == 2)
            {
                up1 = (up1 * down2 - up2 * down1);
                down1 = down1 * down2;
                up2 = gcd(up1, down1);
                up1 = up1 / up2;
                down1 = down1 / up2;
                result = up1.ToString() + "/" + down1.ToString();
                return result;
            }
            if (type == 3)
            {
                up1 = up1 * up2;
                down1 = down1 * down2;
                up2 = gcd(up1, down1);
                up1 = up1 / up2;
                down1 = down1 / up2;
                result = up1.ToString() + "/" + down1.ToString();
                return result;
            }
            if (type == 4)
            {
                up1 = up1 * down2;
                down1 = down1 * up2;
                up2 = gcd(up1, down1);
                up1 = up1 / up2;
                down1 = down1 / up2;
                result = up1.ToString() + "/" + down1.ToString();
                return result;
             
            }
           
            return result;
        }
        public string CalculateZfengsu(int up1,int down1)//判断及生成真分数
        {
            string result = "true";
            int mid = 0;
            
                if (up1 > down1)
                {
                    mid = down1;
                    down1 = up1;
                    up1 = mid;
                    result = up1.ToString() + "/" + down1.ToString();
                    return result;
                }
                    if (up1 == down1)
                    {
                        down1 += 3;
                        result = up1.ToString() + "/" + down1.ToString();
                        return result;
                    }

                    
                
                
          
            return result;
        }