#include <bits/stdc++.h>
using namespace std;
#define int long long;
signed main()
{
    int c, v0, v1, a, b;
    cin >> c >> v0 >> v1 >> a >> b;
    int tmp = v0, day = 0;
    bool flag = true;
    while(c > 0)
    {
        c -= v0;
        if(c <= 0)
        {
            break;
        }
        if(v0 > v1)
        {
            v0 = v1; 
            flag = false;
        }
        if(v0 != tmp)
        {
            c += b;
        }
        if(flag) v0 += a;
        day++;
    }
    cout << day << endl;
    return 0;
}

求调

错误信息：

error: declaration does not declare anything [-fpermissive]