I have tried everything.

Here are some testcases from my algorithm:
0: 10
1: 1
2: 2
3: 3
4: 4
5: 5
6: 6
7: 7
8: 8
9: 9
10: 25
12: 26
14: 27
15: 35
16: 28
18: 29
20: 45
21: 37
24: 38
25: 55
27: 39
28: 47
30: 56

Some big numbers:
16859136: 267778888
16875000: 3555555589
16934400: 355778889
16941456: 277777789
17006112: 48999999
17010000: 555567899
17146080: 256778999
17150000: 1555557778
17203200: 155788888
17210368: 177777888
17222625: 355579999
17280000: 555568889
17287200: 455777789
17294403: 177777777
17360406: 67799999
17364375: 555577799
17418240: 256788899
17496000: 355588999
17500000: 4555555578
17503290: 257777999
17561600: 455777888
17578125: 5555555559
17635968: 67889999
17640000: 555577889
17647350: 556777777
17694720: 256888889
17714700: 255699999
17718750: 2555555799

long long int minimoentero3(long int num)
{
     long long int nf=result;
     return nf;
}


int main()
{
    long int n;
    cin >> n;

    cout<<minimoentero3(n); <- Here the result is sent.
}

Edited by author 26.10.2017 18:28

test
17294403: 177777777

17294403 != 177777777 (5764801)
also
77777777 < 177777777

right answer for this test 377777777