update leetcode

Author: Liang Wang

leetcode/BeautifulArrangement.cpp

@@ -0,0 +1,35 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+class Solution {
+private:
+ int cnt;
+ void solve(int step, vector<bool>& chosen) {
+ if (step <= 1) {
+ ++this->cnt;
+ return;
+ }
+ for (int i = 1; i < chosen.size(); ++i) {
+ if (!chosen[i] && (i % step == 0 || step % i == 0)) {
+ chosen[i] = true;
+ solve(step - 1, chosen);
+ chosen[i] = false;
+ }
+ }
+ }
+public:
+ int countArrangement(int N) {
+ this->cnt = 0;
+ vector<bool> chosen(N + 1, false);
+ solve(N, chosen);
+ return this->cnt;
+ }
+};
+
+int main() {
+ Solution sol;
+ for (int i = 2; i <= 15; ++i) {
+ cout << sol.countArrangement(i) << endl;
+ }
+ return 0;
+}

leetcode/MineSweeper.cpp

@@ -0,0 +1,60 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+typedef pair<int, int> pii;
+const int dir_x[] = {0, 0, 1, 1, 1, -1, -1, -1};
+const int dir_y[] = {-1, 1, -1, 0, 1, -1, 0, 1};
+int get_cnt(const vector<vector<char>>& board, const int x, const int y) {
+ int ret = 0;
+ for (int i = 0; i < 8; ++i) {
+ int nx = x + dir_x[i];
+ int ny = y + dir_y[i];
+ if (nx < 0 || nx >= (int)board.size() || ny < 0 || ny >= (int)board[0].size()) {
+ continue;
+ }
+ ret += (board[nx][ny] == 'X' || board[nx][ny] == 'M');
+ }
+ return ret;
+}
+
+class Solution {
+public:
+ vector<vector<char>> updateBoard(vector<vector<char>>& board, vector<int>& click) {
+ int x = click[0];
+ int y = click[1];
+ if (board[x][y] == 'M') {
+ board[x][y] = 'X';
+ return board;
+ }
+ queue<pii> q;
+ int cnt = get_cnt(board, x, y);
+ board[x][y] = cnt > 0 ? '0' + cnt : 'B';
+ if (cnt == 0) {
+ q.push({x, y});
+ }
+ while (!q.empty()) {
+ pii tp = q.front();
+ q.pop();
+ for (int i = 0; i < 8; ++i) {
+ int nx = tp.first + dir_x[i];
+ int ny = tp.second + dir_y[i];
+ if (nx < 0 || nx >= (int)board.size() || ny < 0 || ny >= (int)board[0].size()) {
+ continue;
+ }
+ if (board[nx][ny] == 'E') {
+ int c = get_cnt(board, nx, ny);
+ board[nx][ny] = c > 0 ? '0' + c : 'B';
+ if (c == 0) {
+ q.push({nx, ny});
+ }
+ }
+ }
+ }
+ return board;
+ }
+};
+
+int main() {
+ Solution sol;
+ return 0;
+}

leetcode/RandomPickWithWeight.cpp

@@ -0,0 +1,29 @@
+
+class Solution {
+private:
+ vector<double> p;
+public:
+ Solution(vector<int> w) {
+ this->p.resize(w.size());
+ int sm = accumulate(w.begin(), w.end(), 0);
+ for (int i = 0; i < (int)w.size(); ++i) {
+ if (i > 0) {
+ this->p[i] = this->p[i - 1] + 1.0 * w[i] / sm;
+ } else {
+ this->p[i] = 1.0 * w[i] / sm;
+ }
+ }
+ }
+
+ int pickIndex() {
+ double rnd = 1.0 * rand() / RAND_MAX;
+ int idx = lower_bound(this->p.begin(), this->p.end(), rnd) - this->p.begin();
+ return idx;
+ }
+};
+
+/**
+ * Your Solution object will be instantiated and called as such:
+ * Solution obj = new Solution(w);
+ * int param_1 = obj.pickIndex();
+ */