661. Image Smoother

Question 1

can you set up variables for img.length, img[0].length?

Answer 1

let m = img.length, n = img[0].length;

Question 2

can you set up variable res for empty two dimensional array?

Answer 2

let m = img.length, n = img[0].length;
let res = new Array(m).fill(0).map(() => new Array(n).fill(0));

Question 3

can you set up variable dir for adjacent cells of current cell in 8 directions?

Answer 3

let m = img.length, n = img[0].length;
let res = new Array(m).fill(0).map(() => new Array(n).fill(0));
let dir = [[0, 1], [1, 0], [0, -1], [-1, 0], [1, 1], [-1, -1], [-1, 1], [1, -1]];

Question 4

can you set up a function smooth that takes coordinates (i, j)?

Answer 4

let m = img.length, n = img[0].length;
let res = new Array(m).fill(0).map(() => new Array(n).fill(0));
let dir = [[0, 1], [1, 0], [0, -1], [-1, 0], [1, 1], [-1, -1], [-1, 1], [1, -1]];
const smooth = (i, j) => {

}

Question 5

can you set up variable sum with initial value current img cell, variable count with initial value 1 in smooth function?

Answer 5

let m = img.length, n = img[0].length;
let res = new Array(m).fill(0).map(() => new Array(n).fill(0));
let dir = [[0, 1], [1, 0], [0, -1], [-1, 0], [1, 1], [-1, -1], [-1, 1], [1, -1]];
const smooth = (i, j) => {
let sum = img[i][j], count = 1;

}

Question 6

can you loop through directions in dir in smooth function?

Answer 6

let m = img.length, n = img[0].length;
let res = new Array(m).fill(0).map(() => new Array(n).fill(0));
let dir = [[0, 1], [1, 0], [0, -1], [-1, 0], [1, 1], [-1, -1], [-1, 1], [1, -1]];
const smooth = (i, j) => {
let sum = img[i][j], count = 1;
for (let [r, c] of dir) {

    }
   
}

Question 7

can you check in the dir loop, if adjacent cell is undefined, if not, update sum with the adjacent cell value, increment count

Answer 7

let m = img.length, n = img[0].length;
let res = new Array(m).fill(0).map(() => new Array(n).fill(0));
let dir = [[0, 1], [1, 0], [0, -1], [-1, 0], [1, 1], [-1, -1], [-1, 1], [1, -1]];
const smooth = (i, j) => {
let sum = img[i][j], count = 1;
for (let [r, c] of dir) {
if (img[i + r] !== undefined && img[i + r][j + c] !== undefined) {
sum += img[i + r][j + c];
count++;
}
}

}

Question 8

can you return average of the sum in the smooth function?

Answer 8

let m = img.length, n = img[0].length;
let res = new Array(m).fill(0).map(() => new Array(n).fill(0));
let dir = [[0, 1], [1, 0], [0, -1], [-1, 0], [1, 1], [-1, -1], [-1, 1], [1, -1]];
const smooth = (i, j) => {
let sum = img[i][j], count = 1;
for (let [r, c] of dir) {
if (img[i + r] !== undefined && img[i + r][j + c] !== undefined) {
sum += img[i + r][j + c];
count++;
}
}
return sum / count | 0;
}

Question 9

can you loop through each cell as input in smooth function, assign smooth function return value to empty two dimensional array?

Answer 9

let m = img.length, n = img[0].length;
let res = new Array(m).fill(0).map(() => new Array(n).fill(0));
let dir = [[0, 1], [1, 0], [0, -1], [-1, 0], [1, 1], [-1, -1], [-1, 1], [1, -1]];
const smooth = (i, j) => {
let sum = img[i][j], count = 1;
for (let [r, c] of dir) {
if (img[i + r] !== undefined && img[i + r][j + c] !== undefined) {
sum += img[i + r][j + c];
count++;
}
}
return sum / count | 0;
}
for (let i = 0; i < m; i++) {
for (let j = 0; j < n; j++) {
res[i][j] = smooth(i, j);
}
}

Question 10

can you return the two dimensional array?

Answer 10

return res;