题目：

题解：

func maximalRectangle(matrix [][]byte) (ans int) {if len(matrix) == 0 {return}m, n := len(matrix), len(matrix[0])left := make([][]int, m)for i, row := range matrix {left[i] = make([]int, n)for j, v := range row {if v == '0' {continue}if j == 0 {left[i][j] = 1} else {left[i][j] = left[i][j-1] + 1}}}for j := 0; j < n; j++ { // 对于每一列，使用基于柱状图的方法up := make([]int, m)down := make([]int, m)stk := []int{}for i, l := range left {for len(stk) > 0 && left[stk[len(stk)-1]][j] >= l[j] {stk = stk[:len(stk)-1]}up[i] = -1if len(stk) > 0 {up[i] = stk[len(stk)-1]}stk = append(stk, i)}stk = nilfor i := m - 1; i >= 0; i-- {for len(stk) > 0 && left[stk[len(stk)-1]][j] >= left[i][j] {stk = stk[:len(stk)-1]}down[i] = mif len(stk) > 0 {down[i] = stk[len(stk)-1]}stk = append(stk, i)}for i, l := range left {height := down[i] - up[i] - 1area := height * l[j]ans = max(ans, area)}}return
}func max(a, b int) int {if a > b {return a}return b
}