分数—蓝桥杯

#include <bits/stdc++.h>
#define endl '\n'
#define int long long
using namespace std;
constexpr int N = 1e6 + 10, inf = 0x3f3f3f3f;
int a[N];
#define x first
#define y second
typedef pair<int, int> pii;
pii pre[N];
void solve()
{
    int n = 20;
    int cnt = 1;
    for (int i = 1; i <= n; i++)
    {
        cnt *= 2;
    }
    int a = 1;
    pre[1] = { 1, 1 };
    int tempp = 1;
    for (int i = 2; i <= n; i++)
    {
        tempp *= 2;
        pre[i].y = tempp;
        int temp = cnt / pre[i].y;
        pre[i].x = temp;
        pre[i].y = cnt;
        //cout << pre[i].x << ' '<<pre[i].y << endl;
    }
    pre[1] = { cnt, cnt };
    int sum1 = 0;
    for (int i = 1; i <= n; i++)
    {
        sum1 += pre[i].x;
    }
    //bug;
    for (int i = 2; i <= cnt; i++)
    {
        while (sum1 % i == 0 && cnt % i == 0)
        {
            sum1 /= i;
            cnt /= i;
        }
    }
    cout << sum1 << '/' << cnt;
}

signed main()
{
    ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
    int T = 1;
    while (T--)
    {
        solve();
    }
    return 0;
}