函数还是一如既往的好用

#include <iostream>
using namespace std;
bool rel(int n, int x)
{
    int m = n;
    while (m > 0)
    {
        if (m % 10 == x)
        {
            return true;
        }
        m /= 10;
    }
    return false;
}
int main()
{
    int x, m, n, s = 0;
    cin >> x >> m >> n;
    for (int i = m; i <= n; i++)
    {
        if (rel(i, x))
        {
            s++;
        }
    }
    cout << s;
    return 0;
}

#include <bits/stdc++.h>
using namespace std;
bool maim(int n, int m){
    while (n > 0){
        if (n % 10 == m) return true;
        n /= 10;
    }
    return false;
}
int main(){
    int l, r, n, num = 0;
    cin >> n >> l >> r;
    for (int i = l; i <= r; i++)if (maim(i, n)) num++;
    cout << num;
}

#include<bits/stdc++.h>
using namespace std;
int main()
{
    int x,m,n,ans=0;
    cin>>x>>m>>n;
    for (int i=m;i<=n;i++)
        if (i/1000==x||i/100%10==x||i/10%10==x||i%10==x)
            ans++;
    cout<<ans;
    return 0;
}