updated C++ solution Google Code Jam Round 2 2016 issue: #50

GoogleCodeJam/2016/Round 2/The Gardener of Seville /solutions/CPP/solution_01.cpp

@@ -0,0 +1,152 @@
+#include <iostream>
+#include <cstring>
+
+using namespace std;
+
+const int maxR = 100;
+const int maxN = maxR * 4;
+const int maxM = maxN / 2;
+
+int m1[maxM], m2[maxM];
+int d[maxM];
+
+char map[maxR][maxR];
+int r, c;
+int n;
+
+const int fx[4] = {-1, 0, 1, 0};
+const int fy[4] = {0, -1, 0, 1};
+
+void getXyf(int i, int& x, int& y, int& f)
+{
+    if (i < c)
+    {
+        x = -1;
+        y = i;
+        f = 2;
+    }
+    else if (i < c + r)
+    {
+        x = i - c;
+        y = c;
+        f = 1;
+    }
+    else if (i < c + r + c)
+    {
+        x = r;
+        y = c - 1 - (i - (c + r));
+        f = 0;
+    }
+    else
+    {
+        x = r - 1 - (i - (c + r + c));
+        y = -1;
+        f = 3;
+    }
+}
+
+bool draw(int from, int to)
+{
+    int x1, y1, f1, x2, y2, f2;
+
+    getXyf(from, x1, y1, f1);
+    getXyf(to, x2, y2, f2);
+
+    while (true)
+    {
+        // move
+        x1 += fx[f1];
+        y1 += fy[f1];
+
+        if (x1 < 0 || x1 >= r || y1 < 0 || y1 >= c)
+        {
+            if (x1 == x2 && y1 == y2)
+            {
+                return true;
+            }
+            return false;
+        }
+
+        if (map[x1][y1] == ' ')
+        {
+            if (f1 & 1)
+            {
+                map[x1][y1] = '/';
+            }
+            else
+            {
+                map[x1][y1] = '\\';
+            }
+        }
+
+        if (map[x1][y1] == '/')
+        {
+            f1 = f1 ^ 3;
+        }
+        else if (map[x1][y1] == '\\')
+        {
+            f1 = f1 ^ 1;
+        }
+    }
+}
+
+bool draw(int j)
+{
+    if ((m2[j] - m1[j] + n) % n <= n / 2)
+    {
+        return draw(m1[j], m2[j]);
+    }
+    else
+    {
+        return draw(m2[j], m1[j]);
+    }
+}
+
+int main()
+{
+    int ct, t;
+    cin >> ct;
+    for (int t = 1; t <= ct; t++)
+    {
+        cin >> r >> c;
+        n = r * 2 + c * 2;
+
+        for (int i = 0; i < n / 2; i ++)
+        {
+            cin >> m1[i] >> m2[i];
+            m1[i] --;
+            m2[i] --;
+            d[i] = (m1[i] + n - m2[i]) % n;
+            if (n - d[i] < d[i])
+            {
+                d[i] = n - d[i];
+            }
+        }
+
+        memset(map, ' ', sizeof(map));
+        for (int i = 1; i <= n / 2; i ++)
+            for (int j = 0; j < n / 2; j ++)
+                if (d[j] == i)
+                {
+                    if (!draw(j))
+                    {
+                        goto impossible;
+                    }
+                }
+
+        cout << "Case #" << t << ":" << endl;
+        for (int i = 0; i < r; i ++)
+        {
+            for (int j = 0; j < c; j ++)
+            {
+                cout << (map[i][j] == ' ' ? '/' : map[i][j]);
+            }
+            cout << endl;
+        }
+        continue;
+impossible:
+        cout << "Case #" << t << ":" << endl;
+        cout << "IMPOSSIBLE" << endl;
+    }
+    return 0;
+}