leetcode.547https://leetcode-cn.com/problems/number-of-provinces/
class Solution {
public:
int findCircleNum(vector<vector<int>>& isConnected) {
function<void(int)> dfs = [&](int x) -> void {
isConnected[x][x] = 0;
for (int i = 0; i < isConnected.size(); i++) {
if (isConnected[x][i] == 1 && isConnected[i][i] == 1) {
dfs(i);
}
}
};
int ans = 0;
for (int i = 0; i < isConnected.size(); i++) {
if (isConnected[i][i] == 1) {
dfs(i);
ans++;
}
}
return ans;
}
};