《算法竞赛入门经典》第2章 循环结构程序设计

 1 #include <stdio.h>
 2 #include <math.h>
 3 
 4 int main()
 5 {
 6     int a, b, n;
 7     double m;
 8 
 9     for (a = 1; a <= 9; a++)
10         for (b = 0; b <= 9; b++)
11     {
12         n = a * 1100 + b * 11;
13         m = sqrt(n);
14         if (floor(m + 0.5) == m)
15             printf("%d\n", n);
16     }
17 
18     return 0;
19 }

 1 #include <stdio.h>
 2 
 3 int main()
 4 {
 5     int x, n, high, low;
 6 
 7     for (x = 1; ; x++)
 8     {
 9         n = x * x;
10         if (n < 1000) continue;
11         if (n > 9999) break;
12         high = n / 100;
13         low  = n % 100;
14         if (high/10 == high%10 && low/10 == low%10)
15             printf("%d\n", n);
16     }
17 
18     return 0;
19 }