RosettaCodeData/Task/Solve-a-Numbrix-puzzle/C++/solve-a-numbrix-puzzle.cpp
2015-11-18 06:14:39 +00:00

155 lines
3.5 KiB
C++

#include <vector>
#include <sstream>
#include <iostream>
#include <iterator>
#include <cstdlib>
#include <string>
#include <bitset>
using namespace std;
typedef bitset<4> hood_t;
struct node
{
int val;
hood_t neighbors;
};
class nSolver
{
public:
void solve(vector<string>& puzz, int max_wid)
{
if (puzz.size() < 1) return;
wid = max_wid;
hei = static_cast<int>(puzz.size()) / wid;
max = wid * hei;
int len = max, c = 0;
arr = vector<node>(len, node({ 0, 0 }));
weHave = vector<bool>(len + 1, false);
for (const auto& s : puzz)
{
if (s == "*") { max--; arr[c++].val = -1; continue; }
arr[c].val = atoi(s.c_str());
if (arr[c].val > 0) weHave[arr[c].val] = true;
c++;
}
solveIt(); c = 0;
for (auto&& s : puzz)
{
if (s == ".")
s = std::to_string(arr[c].val);
c++;
}
}
private:
bool search(int x, int y, int w, int dr)
{
if ((w > max && dr > 0) || (w < 1 && dr < 0) || (w == max && weHave[w])) return true;
node& n = arr[x + y * wid];
n.neighbors = getNeighbors(x, y);
if (weHave[w])
{
for (int d = 0; d < 4; d++)
{
if (n.neighbors[d])
{
int a = x + dx[d], b = y + dy[d];
if (arr[a + b * wid].val == w)
if (search(a, b, w + dr, dr))
return true;
}
}
return false;
}
for (int d = 0; d < 4; d++)
{
if (n.neighbors[d])
{
int a = x + dx[d], b = y + dy[d];
if (arr[a + b * wid].val == 0)
{
arr[a + b * wid].val = w;
if (search(a, b, w + dr, dr))
return true;
arr[a + b * wid].val = 0;
}
}
}
return false;
}
hood_t getNeighbors(int x, int y)
{
hood_t retval;
for (int xx = 0; xx < 4; xx++)
{
int a = x + dx[xx], b = y + dy[xx];
if (a < 0 || b < 0 || a >= wid || b >= hei)
continue;
if (arr[a + b * wid].val > -1)
retval.set(xx);
}
return retval;
}
void solveIt()
{
int x, y, z; findStart(x, y, z);
if (z == 99999) { cout << "\nCan't find start point!\n"; return; }
search(x, y, z + 1, 1);
if (z > 1) search(x, y, z - 1, -1);
}
void findStart(int& x, int& y, int& z)
{
z = 99999;
for (int b = 0; b < hei; b++)
for (int a = 0; a < wid; a++)
if (arr[a + wid * b].val > 0 && arr[a + wid * b].val < z)
{
x = a; y = b;
z = arr[a + wid * b].val;
}
}
vector<int> dx = vector<int>({ -1, 1, 0, 0 });
vector<int> dy = vector<int>({ 0, 0, -1, 1 });
int wid, hei, max;
vector<node> arr;
vector<bool> weHave;
};
//------------------------------------------------------------------------------
int main(int argc, char* argv[])
{
int wid; string p;
//p = ". . . . . . . . . . . 46 45 . 55 74 . . . 38 . . 43 . . 78 . . 35 . . . . . 71 . . . 33 . . . 59 . . . 17 . . . . . 67 . . 18 . . 11 . . 64 . . . 24 21 . 1 2 . . . . . . . . . . ."; wid = 9;
//p = ". . . . . . . . . . 11 12 15 18 21 62 61 . . 6 . . . . . 60 . . 33 . . . . . 57 . . 32 . . . . . 56 . . 37 . 1 . . . 73 . . 38 . . . . . 72 . . 43 44 47 48 51 76 77 . . . . . . . . . ."; wid = 9;
p = "17 . . . 11 . . . 59 . 15 . . 6 . . 61 . . . 3 . . . 63 . . . . . . 66 . . . . 23 24 . 68 67 78 . 54 55 . . . . 72 . . . . . . 35 . . . 49 . . . 29 . . 40 . . 47 . 31 . . . 39 . . . 45"; wid = 9;
istringstream iss(p); vector<string> puzz;
copy(istream_iterator<string>(iss), istream_iterator<string>(), back_inserter<vector<string> >(puzz));
nSolver s; s.solve(puzz, wid);
int c = 0;
for (const auto& s : puzz)
{
if (s != "*" && s != ".")
{
if (atoi(s.c_str()) < 10) cout << "0";
cout << s << " ";
}
else cout << " ";
if (++c >= wid) { cout << endl; c = 0; }
}
cout << endl << endl;
return system("pause");
}