09 Sept 2026•Go / Python / TypeScript•Easy

Delete Columns to Make Sorted

Count string-grid columns that are not sorted from top to bottom.

View original LeetCode question

Inspect each column and count it once as soon as any adjacent row pair is descending.

complexity

O(rows * columns) time and O(1) space.

solution files

Go delete-columns-to-make-sorted/solution.go
Python delete-columns-to-make-sorted/solution.py
TypeScript delete-columns-to-make-sorted/solution.ts

Solution files

Go•delete-columns-to-make-sorted/solution.go

package main

func minDeletionSize(strs []string) int {
	deleted := 0
	for column := range strs[0] {
		for row := 1; row < len(strs); row++ {
			if strs[row][column] < strs[row-1][column] {
				deleted++
				break
			}
		}
	}
	return deleted
}

Python•delete-columns-to-make-sorted/solution.py

class Solution:
    def minDeletionSize(self, strs: list[str]) -> int:
        return sum(any(strs[row][column] < strs[row - class="syntax-number">1][column] for row in range(class="syntax-number">1, len(strs))) for column in range(len(strs[class="syntax-number">0])))

TypeScript•delete-columns-to-make-sorted/solution.ts

function minDeletionSize(strs: string[]): number {
  let deleted = class="syntax-number">0;
  for (let column = class="syntax-number">0; column < strs[class="syntax-number">0].length; column += class="syntax-number">1) for (let row = class="syntax-number">1; row < strs.length; row += class="syntax-number">1) if (strs[row][column] < strs[row - class="syntax-number">1][column]) { deleted += class="syntax-number">1; break; }
  return deleted;
}