Create find-all-possible-stable-binary-arrays-i.py

Author: kamyu104

Python/find-all-possible-stable-binary-arrays-i.py

@@ -0,0 +1,51 @@
+# Time:  O(n * m)
+# Space: O(n * m)
+
+# dp
+class Solution(object):
+    def numberOfStableArrays(self, zero, one, limit):
+        """
+        :type zero: int
+        :type one: int
+        :type limit: int
+        :rtype: int
+        """
+        MOD = 10**9+7
+        dp = [[[0]*2 for _ in xrange(one+1)] for _ in xrange(zero+1)]
+        for i in xrange(zero+1):
+            dp[i][0][0] = 1 if i <= limit else 0
+        for j in xrange(one+1):
+            dp[0][j][1] = 1 if j <= limit else 0
+        for i in xrange(1, zero+1):
+            for j in xrange(1, one+1):
+                dp[i][j][0] = (dp[i-1][j][0]+dp[i-1][j][1])%MOD
+                dp[i][j][1] = (dp[i][j-1][0]+dp[i][j-1][1])%MOD
+                if i-limit-1 >= 0:
+                    dp[i][j][0] = (dp[i][j][0]-dp[i-limit-1][j][1])%MOD
+                if j-limit-1 >= 0:
+                    dp[i][j][1] = (dp[i][j][1]-dp[i][j-limit-1][0])%MOD
+        return (dp[-1][-1][0]+dp[-1][-1][1])%MOD
+
+
+# Time:  O(n * m * l)
+# Space: O(n * m)
+# dp
+class Solution2(object):
+    def numberOfStableArrays(self, zero, one, limit):
+        """
+        :type zero: int
+        :type one: int
+        :type limit: int
+        :rtype: int
+        """
+        MOD = 10**9+7
+        dp = [[[0]*2 for _ in xrange(one+1)] for _ in xrange(zero+1)]
+        dp[0][0][0] = dp[0][0][1] = 1
+        for i in xrange(zero+1):
+            for j in xrange(one+1):
+                for k in xrange(1, limit+1):
+                    if i-k >= 0:
+                        dp[i][j][0] = (dp[i][j][0]+dp[i-k][j][1])%MOD
+                    if j-k >= 0:
+                        dp[i][j][1] = (dp[i][j][1]+dp[i][j-k][0])%MOD
+        return (dp[-1][-1][0]+dp[-1][-1][1])%MOD