62-U型数字

https://nanti.jisuanke.com/t/20683

#include <iostream>
using namespace std;

int main(){
	int ct = 0;
	for(int i = 99; i <= 100000; i++){
		int a[8], len = 0;
		int j = i;
		while(j){
			a[len++] = j % 10;
			j /= 10;
		}
		int k, jian = 0, zeng = 0;
		for(k = 1; k < len; k++){
			if(a[k] < a[k - 1]){
				jian = 1;
				if(zeng)	//上升后又下降，就不合题意
					break;
			}
			else if(a[k] > a[k - 1] && jian){
				zeng = 1;
			}
			else
				break;
		}
		if(k >= len && zeng)  //并且有增有降
			ct++;
	}
	cout << ct << endl;
	return 0;
}