UV problem solution: 10213-how many pieces of land?

I use this formula to calculate: F (n) = (n, 4) + (n, 2) + 1. Detailed explanation is available here.

I really need to implement a big integer class. The following code is rather ugly.

Code:

1. /*************************************** **********************************
2. * Copyright (c) 2008 by liukaipeng *
3. * Liukaipeng at gmail dot com *
4. **************************************** *********************************/
6. /* @ Judge_id 00000 10213 C ++ "how many pieces of land? "*/
8. # Include <algorithm>
9. # Include <cstdio>
10. # Include <cstring>
11. # Include <deque>
12. # Include <fstream>
13. # Include <iostream>
14. # Include <list>
15. # Include <map>
16. # Include <queue>
17. # Include <set>
18. # Include <stack>
19. # Include <string>
20. # Include <vector>
22. Using namespace STD;
24. Typedef unsigned long ulonglong;
26. String add (string const & X, string const & Y)
27. {
28. Int sumlen = max (X. Size (), Y. Size () + 1;
29. String sum (sumlen, '0'), xtmp (sumlen, '0'), ytmp (sumlen, '0 ');
30. Int xstart = sumlen-X. Size (), ystart = sumlen-y. Size ();
31. Copy (X. Begin (), X. End (), xtmp. Begin () + xstart );
32. Copy (Y. Begin (), Y. End (), ytmp. Begin () + ystart );
33. For (INT I = sumlen-1, S, carry = 0; I> = 0; -- I, carry = s/10)
34. Sum [I] = (S = xtmp [I] + ytmp [I]-'0'-'0' + carry) % 10 + '0 ';
35. For (; sum [0] = '0'; sum. Erase (0, 1 )){}
36. Return sum;
37. }
39. String muladd (ulonglong X, ulonglong y, ulonglong Z)
40. {
41. Int const shift = 31;
42. Ulonglong X1 = x> shift, X2 = x & (1ll <shift)-1 );
43. Ulonglong Y1 = Y> shift, y2 = Y & (1ll <shift)-1 );
44. Ulonglong z1 = z> shift, Z2 = Z & (1ll <shift)-1 );
45. Ulonglong high = x1 * Y1, mid = x1 * y2 + x2 * Y1 + Z1, low = x2 * y2 + Z2;
46. String TMP;
47. For (; high! = 0; high/= 10)
48. TMP. append (1, high % 10 + '0 ');
49. String highs (TMP. rbegin (), TMP. rend ());
50. For (TMP. Clear (); Mid! = 0; Mid/= 10)
51. TMP. append (1, mid % 10 + '0 ');
52. String mids (TMP. rbegin (), TMP. rend ());
53. For (TMP. Clear (); low! = 0; low/= 10)
54. TMP. append (1, low % 10 + '0 ');
55. String lows (TMP. rbegin (), TMP. rend ());
57. For (INT I = 0; I <shift * 2; ++ I)
58. Highs = add (highs, highs );
59. For (INT I = 0; I <shift; ++ I)
60. Mids = add (MIDS, MIDS );
61. String Product = add (highs, MIDS );
62. Product = add (product, lows );
63. Return product;
64. }
66. Int main (INT argc, char * argv [])
67. {
68. # Ifndef online_judge
69. Freopen (string (argv [0]) + ". In"). c_str (), "r", stdin );
70. Freopen (string (argv [0]) + ". Out"). c_str (), "W", stdout );
71. # Endif
73. /* F (n) = (n, 4) + (n, 2) + 1 */
74. Int ncases;
75. Cin> ncases;
76. While (ncases --> 0 ){
77. Ulonglong N;
78. Cin> N;
79. If (n <4 ){
80. Ulonglong fn = 1;
81. For (INT I = 1; I <n; ++ I)
82. FN * = 2;
83. Cout <FN <'/N ';
84. } Else if (n <1 <16 ){
85. Ulonglong fn = N * (n-1)/2*(n-2)/3 * (n-3)/4;
86. FN + = n % 2 = 0? N/2 * (n-1): (n-1)/2 * N;
87. FN + = 1;
88. Cout <FN <'/N ';
89. } Else {
90. Ulonglong x = N * (n-1)/2, y = (n-2) * (n-3)/2;
91. If (X % 2 = 0) x/= 2;
92. Else y/= 2;
93. If (X % 3 = 0) x/= 3;
94. Else y/= 3;
95. Ulonglong z = (N % 2 = 0? N/2 * (n-1): (n-1)/2 * n );
96. Z + = 1;
97. String fn = muladd (x, y, z );
98. Cout <FN <'/N ';
99. }
100. }
102. Return 0;
103. }
104.