题解

#include<bits/stdc++.h>
using namespace std;
int a[10];
int main(){
    int n,i1,cnt = 0,p = 1;
    cin >> n;
    a[0] = 9999999;
    for(int i = 1;i <= n;i++){
    	int l = 1;
    	i1 = i;
        while(i1){
        	a[p] = i1 % 10;
            i1 /= 10;
            if(a[p - 1] < a[p]){
                l = 0;
            	break;
            }
            p++;
        }
        if(l){
            cnt++;
        }
        for(int i = 1;i <= p;i++){
            a[i] = 0;
        }
        p = 1;
        l = 1;
    }
    cout << cnt;
	return 0;
}