Go | Brute Force | Followed the hints
Intuition\n Describe your first thoughts on how to solve this problem. \nStarted to think about trying to do some sort of prefix-y sum solution. Soon found that
# Intuition\n<!-- Describe your first thoughts on how to solve this problem. -->\nStarted to think about trying to do some sort of prefix-y sum solution. Soon found that any optimization gains from a solution like that would probably be outweighed by the complexity of the solution. Personally dont think I could implement something like that within any reaonsable timeframe without too much debugging. Instead resotred to looking at the hint and implemented what it said.\n\n# Approach\n<!-- Describe your approach to solving the problem. -->\n\n# Complexity\n- Time complexity:\n<!-- Add your time complexity here, e.g. $$O(n)$$ -->\nO(N*M)\n\n- Space complexity:\n<!-- Add your space complexity here, e.g. $$O(n)$$ -->\nO(N*M)\n\n# Code\n```\nfunc resultGrid(image [][]int, threshold int) [][]int {\n    N, M := len(image), len(image[0])\n    sum := make([][]int, N)\n    num := make([][]int, N)\n    for i := range sum {\n        sum[i] = make([]int, M)\n        num[i] = make([]int, M)\n    }\n\n    for i := 0; i < N; i++ {\n        for j := 0; j < M; j++ {\n            traverseRegion(i, j, N, M, threshold, sum, num, image)\n        }\n    }\n    \n    res := make([][]int, N)\n    for i := 0; i < N; i++ {\n        res[i] = make([]int, M)\n        for j := 0; j < M; j++ {\n            v := image[i][j]\n            if num[i][j] > 0 {\n                v = sum[i][j] / num[i][j]\n            }\n            res[i][j] = v            \n        }\n    }\n    return res\n}\n\nvar xDir = []int{0, 1}\nvar yDir = []int{-1, 0}\n\nfunc traverseRegion(row, col, N, M, t int, sum, num [][]int, image [][]int) {\n    avg := 0\n    for i := row; row+3 <= N && i < row+3; i++ {\n        for j := col; col+3 <= M && j < col+3; j++ {\n            for d := 0; d < 2; d++ {\n                adji, adjj := i+xDir[d], j+yDir[d]                \n                if adji >= row && adji < row+3 && adjj >= col && adjj < col+3 && \n                    abs(image[i][j] - image[adji][adjj]) > t {                        \n                        return\n                    }\n            }\n            avg += image[i][j]\n        }\n    }\n    for i := row; row+3 <= N && i < row+3; i++ {\n        for j := col; col+3 <= M && j < col+3; j++ {            \n            sum[i][j] = sum[i][j] + (avg / 9)\n            num[i][j]++\n        }\n    }\n}\n\nfunc abs(x int) int { \n    if x < 0 { return -x }\n    return x \n}\n```
['Go']