leetcode_59_solution_1.py

def generateMatrix(self, n: int) -> List[List[int]]:
    numLayers = (n+1)//2
    ret = [[0]*n for x in range(0, n)]
    cnt = 1
    for layer in range(0, numLayers):
        # Fill the top row of layer
        for i in range(layer, n-layer):
            ret[layer][i] = cnt
            cnt += 1

        # Fill right side of layer
        for i in range(layer+1, n-layer):
            ret[i][n-layer-1] = cnt
            cnt += 1

        # Fill bottom side
        for i in range(n-layer-1-1, layer-1, -1):
            ret[n-layer-1][i] = cnt
            cnt += 1

        # Fill left side
        for i in range(n-layer-1-1, layer, -1):
            ret[i][layer] = cnt
            cnt += 1

    return ret