UVa 11259 - Coin Changing Again

#Dynamic Programming #Sport Programming #UVa

Table of Contents

This took lot of my time and I managed to come up with this Top-down Dynamic Programming solution. This approach times out. Any suggestions? Problem Statement : http://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=2226\\

 1# include <cstdio>
 2# include <map>
 3# include <set>
 4using namespace std;
 5struct State
 6{
 7 State (int v1, int v2, int v3, int v4)
 8 {
 9  V1 = v1; V2 = v2; V3 = v3; V4 = v4;
10 }
11 int getPart2(int Value = 0)
12 {
13  int Part2 = 0;
14  Part2 = (V4 >> 13);
15  Part2 |= (Value << 4);
16  return Part2;
17 }
18 unsigned long long getPart1()
19 {
20  unsigned long long Part1 = 0;
21  Part1 = V1;
22  Part1 |= (V2 << 17);
23  Part1 |= ((unsigned long long)V3 << 34);
24  Part1 |= ((unsigned long long)V4 << 51);
25  return Part1;
26 }
27 int V1, V2, V3, V4;
28};
29map <int, set<unsigned long long> > States;
30map <int, set<unsigned long long> > Solutions;
31int c1, c2, c3, c4, q, d1, d2, d3, d4, v;
32unsigned long long Result ;
33bool CheckVisited (unsigned long long Part1, int Part2)
34{
35 if (States[Part2].count (Part1)) return true;
36 States[Part2].insert (Part1);
37 return false;
38}
39void Solution (State & s, int Value)
40{
41 unsigned long long Part1 = s.getPart1();
42 int Part2 = s.getPart2(Value);
43 if (!Value)
44 {
45  Solutions[Part2].insert (Part1);
46  return;
47 }
48 if (CheckVisited(Part1, Part2)) return;
49 if (s.V1 - 1 >= 0 && Value - c1 >= 0)
50 {
51  s.V1--;
52  Solution (s, Value - c1);
53  s.V1++;
54 }
55 if (s.V2 - 1 >= 0 && Value - c2 >= 0)
56 {
57  s.V2--;
58  Solution (s, Value - c2);
59  s.V2++;
60 }
61 if (s.V3 - 1 >= 0 && Value - c3 >= 0)
62 {
63  s.V3--;
64  Solution (s, Value - c3);
65  s.V3++;
66 }
67 if (s.V4 - 1 >= 0 && Value - c4 >= 0)
68 {
69  s.V4--;
70  Solution (s, Value - c4);
71  s.V4++;
72 }
73}
74int main()
75{
76 freopen ("Input.txt", "r", stdin);
77 freopen ("Scratch.txt", "w", stdout);
78 int N;
79 scanf ("%d", &N);
80 State s (0, 0, 0, 0);
81 while (N--)
82 {
83  scanf ("%d%d%d%d%d", &c1, &c2, &c3, &c4, &q);
84  while (q--)
85  {
86   scanf ("%d%d%d%d%d", &s.V1, &s.V2, &s.V3, &s.V4, &v);
87   Result = 0;
88   States.clear();
89   Solutions.clear();
90   Solution (s, v);
91   for (map<int, set<unsigned long long> >::iterator it = Solutions.begin(); it != Solutions.end(); it++)
92    Result += it->second.size();
93   printf ("%lld\n", Result);
94  }
95 }
96}