Update Solution.py

Invalid Syntax error Removed

Author: CodersAcademy006

solution/1000-1099/1074.Number of Submatrices That Sum to Target/Solution.py

@@ -1,21 +1,32 @@
 class Solution:
-    def numSubmatrixSumTarget(self, matrix: List[List[int]], target: int) -> int:
-        def f(nums: List[int]) -> int:
-            d = defaultdict(int)
-            d[0] = 1
-            cnt = s = 0
-            for x in nums:
-                s += x
-                cnt += d[s - target]
-                d[s] += 1
-            return cnt
+  def numSubmatrixSumTarget(self, matrix, target):
+    """
+    :type matrix: List[List[int]]
+    :type target: int
+    :rtype: int
+    """
+    m = len(matrix)
+    n = len(matrix[0])
+    ans = 0
+    for i in range(m):
+      col = [0] * n
+      for j in range(i, m):
+        for k in range(n):
+          col[k] += matrix[j][k]
+        ans += self.f(col, target)
+    return ans
 
-        m, n = len(matrix), len(matrix[0])
-        ans = 0
-        for i in range(m):
-            col = [0] * n
-            for j in range(i, m):
-                for k in range(n):
-                    col[k] += matrix[j][k]
-                ans += f(col)
-        return ans
+  def f(self, nums, target):
+    """
+    :type nums: List[int]
+    :type target: int
+    :rtype: int
+    """
+    d = {0: 1}  # map to store prefix sum counts
+    s = 0
+    cnt = 0
+    for x in nums:
+      s += x
+      cnt += d.get(s - target, 0)  # count subarray sums equal to target
+      d[s] = d.get(s, 0) + 1  # update prefix sum count
+    return cnt