Minimum Number of Flips to Make Binary Grid Palindromic I
<p>You are given an <code>m x n</code> binary matrix <code>grid</code>.</p>

<p>A row or column is considered <strong>palindromic</strong> if its values read the same forward and backward.</p>

<p>You can <strong>flip</strong> any number of cells in <code>grid</code> from <code>0</code> to <code>1</code>, or from <code>1</code> to <code>0</code>.</p>

<p>Return the <strong>minimum</strong> number of cells that need to be flipped to make <strong>either</strong> all rows <strong>palindromic</strong> or all columns <strong>palindromic</strong>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<div class="example-block">
<p><strong>Input:</strong> <span class="example-io">grid = [[1,0,0],[0,0,0],[0,0,1]]</span></p>

<p><strong>Output:</strong> <span class="example-io">2</span></p>

<p><strong>Explanation:</strong></p>

<p><img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/3200-3299/3239.Minimum%20Number%20of%20Flips%20to%20Make%20Binary%20Grid%20Palindromic%20I/images/screenshot-from-2024-07-08-00-20-10.png" style="width: 420px; height: 108px;" /></p>

<p>Flipping the highlighted cells makes all the rows palindromic.</p>
</div>

<p><strong class="example">Example 2:</strong></p>

<div class="example-block">
<p><strong>Input:</strong> <span class="example-io">grid = </span>[[0,1],[0,1],[0,0]]</p>

<p><strong>Output:</strong> <span class="example-io">1</span></p>

<p><strong>Explanation:</strong></p>

<p><img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/3200-3299/3239.Minimum%20Number%20of%20Flips%20to%20Make%20Binary%20Grid%20Palindromic%20I/images/screenshot-from-2024-07-08-00-31-23.png" style="width: 300px; height: 100px;" /></p>

<p>Flipping the highlighted cell makes all the columns palindromic.</p>
</div>

<p><strong class="example">Example 3:</strong></p>

<div class="example-block">
<p><strong>Input:</strong> <span class="example-io">grid = [[1],[0]]</span></p>

<p><strong>Output:</strong> <span class="example-io">0</span></p>

<p><strong>Explanation:</strong></p>

<p>All rows are already palindromic.</p>
</div>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>m == grid.length</code></li>
	<li><code>n == grid[i].length</code></li>
	<li><code>1 &lt;= m * n &lt;= 2 * 10<sup>5</sup></code></li>
	<li><code>0 &lt;= grid[i][j] &lt;= 1</code></li>
</ul>
Array; Two Pointers; Matrix
class Solution {
    public int minFlips(int[][] grid) {
        int m = grid.length, n = grid[0].length;
        int cnt1 = 0, cnt2 = 0;
        for (var row : grid) {
            for (int j = 0; j < n / 2; ++j) {
                if (row[j] != row[n - j - 1]) {
                    ++cnt1;
                }
            }
        }
        for (int j = 0; j < n; ++j) {
            for (int i = 0; i < m / 2; ++i) {
                if (grid[i][j] != grid[m - i - 1][j]) {
                    ++cnt2;
                }
            }
        }
        return Math.min(cnt1, cnt2);
    }
}
