算法模版

1、 二分查找

int left = 0, right = array.length - 1;
while (left <= right) {
    int middle = (left + right) / 2;
    if (array[middle] == target) {
        // find the result
        return middle;
    } else if (array[middle] < target) {
        left = middle + 1;
    } else {
        right = middle - 1;
    }
}

2、广度优先搜索

  void bfs(TreeNode node) {
      Queue<TreeNode> queue = new LinkedList<>();
      Set<TreeNode> visited = new HashSet<>();
      queue.add(node);
      while (!queue.isEmpty()) {
          TreeNode treeNode = queue.poll();
          visited.add(treeNode);
          // 处理当前节点
          process(treeNode);
          // 找到子节点
          List<TreeNode> childNodes = generated(treeNode);
          for (TreeNode childNode : childNodes) {
              if (!visited.contains(childNode)) {
                  queue.offer(childNode);
              }
          }
      }
  }