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

void caculate(int a, int b)
{

    if (b % a == 0)
    {
        b = b / a;
        a = 1;
    }
    if (a == 1)
    {
        cout << a << "/" << b << endl;
        return;
    }
    if (b % (a - 1) == 0)
    {
        cout << 1 << "/" << b / (a - 1) << "+";
        caculate(1, b);
        return;
    }

    cout << 1 << "/" << b / a + 1 << "+";
    caculate(a - b % a, b * (b / a + 1));
}

int main()
{
    string num1;
    string num2;
    getline(cin, num1, '/');
    getline(cin, num2);
    int a, b;
    a = stoi(num1);
    b = stoi(num2);
    caculate(a, b);
}

感觉是比较纯的数学问题

算法参考了