547. Friend Circles

/**
 * @param {number[][]} M
 * @return {number}
 */
var findCircleNum = function (M) {
	let count = 0
	const len = M.length,
		visited = new Array(len).fill(0)
	const dfs = (row) => {
		for (let col = 0; col < len; col++) {
			const person = M[row][col]
			if (person === 1 && visited[col] === 0) {
				visited[col] = 1
				dfs(col)
			}
		}
	}

	for (let row = 0; row < len; row++) {
		if (visited[row] === 0) {
			dfs(row)
			count++
		}
	}
	return count
}

//My attempt (doesn't work)
var findCircleNumFail = function (M) {
	let count = 0
	const len = M.length
	const helper = (i, j) => {
		const recurse = (i, j) => {
			if (!M[i] || j >= len || j < 0) return
			if (M[i][j] === 1) {
				M[i][j] = 2
			} else {
				return
			}

			recurse(i, j + 1)
			recurse(i, j - 1)
			recurse(i + 1, j)
			recurse(i + 1, j - 1)
			recurse(i - 1, j)
			recurse(i - 1, j + 1)
		}
		if (!M[i][j]) {
			return 0
		}
		recurse(i, j)
		return 1
	}

	for (let row = 0; row < len; row++) {
		for (let col = 0; col < len; col++) {
			const person = M[row][col]
			if (person !== 2) {
				temp = helper(row, col)
				count += temp
			}
		}
	}
	return count
}
const arr1 = [
	[1, 1, 0],
	[1, 1, 0],
	[0, 0, 1],
]
const arr2 = [
	[1, 1, 0],
	[1, 1, 1],
	[0, 1, 1],
]
const arr3 = [
	[1, 0, 0, 1],
	[0, 1, 1, 0],
	[0, 1, 1, 1],
	[1, 0, 1, 1],
]
const arr4 = [
	[1, 0, 0, 0],
	[0, 1, 0, 0],
	[0, 0, 1, 0],
	[0, 0, 0, 1],
]
const arr5 = [
	[1, 0, 0, 1, 0],
	[0, 1, 1, 0, 1],
	[0, 1, 1, 1, 0],
	[1, 0, 1, 1, 0],
	[0, 1, 0, 0, 1],
]
const arr6 = [
	[1, 1, 0, 0, 0, 0],
	[1, 1, 0, 0, 0, 0],
	[0, 0, 1, 1, 1, 0],
	[0, 0, 1, 1, 0, 0],
	[0, 0, 1, 0, 1, 0],
	[0, 0, 0, 0, 0, 1],
]

//Test cases
console.log(findCircleNum(arr1)) //2
console.log(findCircleNum(arr2)) //1
console.log(findCircleNum(arr3)) //1
console.log(findCircleNum(arr4)) //4
console.log(findCircleNum(arr5)) //1
console.log(findCircleNum(arr6)) //3