Create Candy.cpp

Candy.cpp

@@ -0,0 +1,49 @@
+/* Gary is a teacher at XYZ school. To reward his N students he bought a packet of N candies all with different flavours. But the problem is some students like certain flavour while some doesn't. Now Gary wants to know the number of ways he can distribute these N candies to his N students such that every student gets exactly one candy he likes.
+Input Format :
+Line 1 : An integer N (1<= N <= 16) denoting number of students and candies.
+Next N lines : N integers describing the preferences of one student. 1 at i'th (0 <= i < N) position denotes that this student likes i'th candy , 0 means he doesn't.
+Assume input to be 0-indexed based.
+Output Format :
+Return the number of ways Gary can distribute these N candies to his N students such that every student gets exactly one candy he likes.``
+Sample Input:
+3
+1 1 1
+1 1 1
+1 1 1
+Sample Output:
+6 */
+
+
+
+int candies(int like[][MAXN], int n, int person, int mask, int *dp)
+{
+    if (person >= n)
+    {
+        return 1;
+    }
+    if(dp[mask]!=0)
+    {
+        return dp[mask];
+    }
+    int ans = 0;
+    for (int i = 0; i < n; i++)
+    {
+        if (!(mask & (1 << i)) && like[person][i])
+        {
+            ans += candies(like, n, person + 1, mask | (1 << i), dp);
+        }
+    }
+    dp[mask]=ans;
+    return ans;
+}
+long long solve(int like[][MAXN],int n)
+{
+	int *dp = new int[1 << n];
+    for (int i = 0; i < (1 << n); i++)
+    {
+        dp[i] = 0;
+    }
+    int ans= candies(like, n, 0, 0, dp);
+    delete[]dp;
+    return ans;
+}