ID

#include<iostream>
#include<vector>

using namespace std;

bool isvalid(int i, int j) {
    int cnt = 0;
    for (int k = 0; k < 10; ++k) {
        if (i%10 != j%10) {
            cnt++;
        }
        i/=10;
        j/=10;
    }
    if (cnt < 2) return false;
    return true;
}

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

    vector<int> foo(1024);
    for (int i = 1; i < 1024; ++i) {
        int t;
        for (t = foo[i-1] + 1;;++t) {
            bool fail = false;
            for (int j = 0;j < i; ++j) {
                if (!isvalid(foo[j], t)) {
                    fail=true;
                    break;
                }
            }
            if (!fail) break;
        }
        foo[i] = t;
    }

    vector<int> ds(10);
    for (int i = 0; i < 10; ++i) {
        ds[i] = foo[n-1]%10;
        foo[n-1]/=10;
    }
    for (int i = 9; i >= 0; --i) {
        cout << ds[i];
    }
    return 0;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED