3 dec 944. Delete Columns to Make Sorted

class Solution {
public:
    int minDeletionSize(vector<string>& A) {
    int n = A.size();
    int m = A[0].size();
    int ans = 0;
    for (int j = 0; j < m; j++) {
        bool sorted = true;
        for (int i = 0; i < n - 1; i++) {
            if (A[i][j] > A[i + 1][j]) {
                sorted = false;
                break;
            }
        }
        if (!sorted) ans++;
    }
    return ans;
}
};