leetcode

1 Random Problem

2 files changed, 56 insertions(+), 0 deletions(-)

diff --git a/ Problems/3249.cpp b/ Problems/3249.cpp

@@ -0,0 +1,55 @@

class Solution {

public:

int countGoodNodes(const vector<vector<int>> &edges) const {

static int count[100001];

const int n = size(edges) + 1;

vector<vector<int>> adj(n);

stack<pair<int, int>> st;

int res = 0;

for (const auto &edge : edges) {

adj[edge[0]].push_back(edge[1]);

adj[edge[1]].push_back(edge[0]);

}

st.emplace(0, -1);

memset(count, 0x00, sizeof(count));

while (!st.empty()) {

if (st.top().first != -1) {

const auto [root, parent] = st.top();

st.emplace(-1, -1);

for (const int next : adj[root]) {

if (next == parent) continue;

st.emplace(next, root);

}

continue;

}

st.pop();

const auto [root, parent] = st.top();

st.pop();

int cnt = 1;

int goal = -1;

bool good = true;

for (int i = 0; i < size(adj[root]); i++) {

const int next = adj[root][i];

if (next == parent) continue;

if (goal == -1)

goal = count[next];

else if (count[next] != goal)

good = false;

cnt += count[next];

}

if (good) res++;

count[root] = cnt;

}

return res;

}

};

diff --git a/ README.md b/ README.md

@@ -1332,3 +1332,4 @@ for solving problems. | 3227 | Medium | [Vowels Game in a String](Problems/3227.cpp) | | 3228 | Medium | [Maximum Number of Operations to Move Ones to the End](Problems/3228.cpp) | | 3239 | Medium | [Minimum Number of Flips to Make Binary Grid Palindromic I](Problems/3239.cpp) |

| 3249 | Medium | [Count the Number of Good Nodes](Problems/3249.cpp) |