题解 | 无限长正整数排列字符串

#include <stdio.h>
#include<string.h>
int main() {
    int n;
    scanf("%d",&n);
    int count=0;
    int num=1;
    char a[20];
    while(1)
    {
        sprintf(a,"%d",num);
        int len=strlen(a);
        if(count+len>=n)
        {
            printf("%c\n",a[n-count-1]);
            break;
        }
        count+=len;
       num++;
    }
    return 0;
}