Find Champion I
<p>There are <code>n</code> teams numbered from <code>0</code> to <code>n - 1</code> in a tournament.</p>

<p>Given a <strong>0-indexed</strong> 2D boolean matrix <code>grid</code> of size <code>n * n</code>. For all <code>i, j</code> that <code>0 &lt;= i, j &lt;= n - 1</code> and <code>i != j</code> team <code>i</code> is <strong>stronger</strong> than team <code>j</code> if <code>grid[i][j] == 1</code>, otherwise, team <code>j</code> is <strong>stronger</strong> than team <code>i</code>.</p>

<p>Team <code>a</code> will be the <strong>champion</strong> of the tournament if there is no team <code>b</code> that is stronger than team <code>a</code>.</p>

<p>Return <em>the team that will be the champion of the tournament.</em></p>

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

<pre>
<strong>Input:</strong> grid = [[0,1],[0,0]]
<strong>Output:</strong> 0
<strong>Explanation:</strong> There are two teams in this tournament.
grid[0][1] == 1 means that team 0 is stronger than team 1. So team 0 will be the champion.
</pre>

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

<pre>
<strong>Input:</strong> grid = [[0,0,1],[1,0,1],[0,0,0]]
<strong>Output:</strong> 1
<strong>Explanation:</strong> There are three teams in this tournament.
grid[1][0] == 1 means that team 1 is stronger than team 0.
grid[1][2] == 1 means that team 1 is stronger than team 2.
So team 1 will be the champion.
</pre>

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

<ul>
	<li><code>n == grid.length</code></li>
	<li><code>n == grid[i].length</code></li>
	<li><code>2 &lt;= n &lt;= 100</code></li>
	<li><code>grid[i][j]</code> is either <code>0</code> or <code>1</code>.</li>
	<li>For all <code>i grid[i][i]</code> is <code>0.</code></li>
	<li>For all <code>i, j</code> that <code>i != j</code>, <code>grid[i][j] != grid[j][i]</code>.</li>
	<li>The input is generated such that if team <code>a</code> is stronger than team <code>b</code> and team <code>b</code> is stronger than team <code>c</code>, then team <code>a</code> is stronger than team <code>c</code>.</li>
</ul>
Array; Matrix
class Solution {
public:
    int findChampion(vector<vector<int>>& grid) {
        int n = grid.size();
        for (int i = 0;; ++i) {
            int cnt = 0;
            for (int j = 0; j < n; ++j) {
                if (i != j && grid[i][j] == 1) {
                    ++cnt;
                }
            }
            if (cnt == n - 1) {
                return i;
            }
        }
    }
};