Spiral Matrix III.py

class Solution:
    def spiralMatrixIII(self, rows: int, cols: int, rStart: int, cStart: int) -> List[List[int]]:
        ans = [[rStart, cStart]]
        val = 1
        i, j = rStart, cStart
        def is_valid(i, j):
            if 0 <= i < rows and 0 <= j < cols:
                return True
            return False
        
        while True:
            if len(ans) == rows * cols:
                return ans
            
            # go right val times
            for _ in range(val):
                j+=1
                if is_valid(i,j):
                    ans.append([i,j])
            # go bottom val times
            for _ in range(val):
                i+=1
                if is_valid(i,j):
                    ans.append([i,j])
            # go left val+1 times
            for _ in range(val+1):
                j-=1
                if is_valid(i,j):
                    ans.append([i,j])
            # go up val+1 times
            for _ in range(val+1):
                i-=1
                if is_valid(i,j):
                    ans.append([i,j])
            val+=2