566. Reshape the Matrix - LeetCode Solution

class Solution:
    def matrixReshape(self, mat: List[List[int]], r: int, c: int) -> List[List[int]]:
        new = []
        
        for i in mat:
            new+= i
        
        ans = []
        count = 0
        if r*c != len(new):
            return mat
        
        for i in range(r):
            a = []
            for j in range(c):
                a.append(new[count])
                count+=1
        
            ans.append(a)

        
        return ans