程序代码：

#define _CRT_SECURE_NO_WARNINGS

#include <stdio.h>

#define LEN  15

void print(int a[], int n)
{
    for (n -= 1; n >= 0; n -= 1)
        printf("%d", a[n]);
    puts("");
}

int GetSum(int a[], int n)
{
    int sum = 0;
    for (int i = 0; i <= n; i += 1)
    {
        sum += a[i] * a[n - i];
    }
    return sum;
}

void fun(int a[], int ip, int flag, int n)
{
    if (ip == n)
    {
        if (a[n-1])  print(a, n);
        return;
    }
    for (a[ip] = 0; a[ip] < 10; a[ip] += 1)
    {
        int sum = GetSum(a, ip) + flag;
        if (sum % 10 != a[ip])  continue;
        fun(a, ip + 1, sum / 10, n);
    }
}

int main( void )
{
    int sa[LEN] = { 0 };

    for (int n = 1; n <= LEN; n += 1)
    {
        fun(sa, 0, 0, n);
    }

    return 0;
}

程序代码：

#include <stdio.h>
#include <math.h>

void main()
{
    int i,j;
    int d;

    scanf("%d",&d);
    for(i=(int)pow(10,d-1);i<(int)pow(10,d);i++)
    {
        for(j=10;j<(int)pow(10,d);j=j*10)
        {
            if(i/j == 0)
                break;
        }

        if(((i*i)%j) == i)
            printf("%d ",i);
    }
    printf("\n");
}