为什么会报错？数组不是都有forEach方法吗
var pacificAtlantic = function(heights) {
if(!heights || !heights[0]) return []
const m = heights.length
const n = heights[0].length
const flow1 = Array.from({length:m},() => new Array(n).fill(false))
const flow2 = Array.from({length:m},() => new Array(n).fill(false))
const dfs = (r,c,flow) => {
flow[r][c] = true
[[r-1, c], [r+1, c], [r, c-1], [r, c+1]].forEach(([nr,nc]) => {
if (
//保证在矩阵中
nr >= 0 && nr < m && nc >= 0 && nr < n &&
//不要重复访问
!flow[nr][nc] &&
//保证逆流而上
heights[nr][nc] >= heights[r][c]
){
dfs(nr,nc,flow)
}
})
}
//沿着海岸线逆流而上
for (let r = 0; r < m; r++) {
dfs(r,0,flow1)
dfs(r,n-1,flow2)
}
for (let c = 0; c < n; c++) {
dfs(0,c,flow1)
dfs(m-1,c,flow2)
}
//收集能流到两个大洋里的坐标
const res = []
for (let r = 0; r < m; r++){
for (let c = 0; c < n; c++) {
if (flow1[r][c] && flow2[r][c]){
res.push([r,c])
}
}
}
return res
};