Smallest square that begins with n: Difference between revisions

</pre>

{{trans|Perl}}

<syntaxhighlight lang="d">

import std.stdio, std.range, std.conv, std.string;

// Choose an arbitrary big integer to make sure brute forcing effective

// FYI at least 45_369+1 for 0 < n < 50

const int upperBound = 1_000_000;

bool isTheBeginningOf(int a, int b) {

return indexOf(to!string(b^^2), to!string(a)) == 0;

}

void main()

{

writefln("Prefix n^2 n");

foreach(i; iota(1, 50)) {

foreach(j; iota(upperBound)) {

if (isTheBeginningOf(i,j)) {

writefln("%4d: %4d^2 = %5d", i, j, j^^2 );

break;

}

}

}

}

</syntaxhighlight>

{{out}}

<pre style='height:50ex;'>

Prefix n^2 n

1: 1^2 = 1

2: 5^2 = 25

3: 6^2 = 36

4: 2^2 = 4

5: 23^2 = 529

6: 8^2 = 64

7: 27^2 = 729

8: 9^2 = 81

9: 3^2 = 9

10: 10^2 = 100

11: 34^2 = 1156

12: 11^2 = 121

13: 37^2 = 1369

14: 12^2 = 144

15: 39^2 = 1521

16: 4^2 = 16

17: 42^2 = 1764

18: 43^2 = 1849

19: 14^2 = 196

20: 45^2 = 2025

21: 46^2 = 2116

22: 15^2 = 225

23: 48^2 = 2304

24: 49^2 = 2401

25: 5^2 = 25

26: 51^2 = 2601

27: 52^2 = 2704

28: 17^2 = 289

29: 54^2 = 2916

30: 55^2 = 3025

31: 56^2 = 3136

32: 18^2 = 324

33: 58^2 = 3364

34: 59^2 = 3481

35: 188^2 = 35344

36: 6^2 = 36

37: 61^2 = 3721

38: 62^2 = 3844

39: 63^2 = 3969

40: 20^2 = 400

41: 203^2 = 41209

42: 65^2 = 4225

43: 66^2 = 4356

44: 21^2 = 441

45: 213^2 = 45369

46: 68^2 = 4624

47: 69^2 = 4761

48: 22^2 = 484

49: 7^2 = 49