During the NBA playoffs, we always arrange the rather strong team to play with the rather weak team, like make the rank 1 team play with the rank nth team, which is a good strategy to make the contest more interesting. Now, you're given n teams, you need to output their final contest matches in the form of a string.

The n teams are given in the form of positive integers from 1 to n, which represents their initial rank. (Rank 1 is the strongest team and Rank n is the weakest team.) We'll use parentheses('(', ')') and commas(',') to represent the contest team pairing - parentheses('(' , ')') for pairing and commas(',') for partition. During the pairing process in each round, you always need to follow the strategy of making the rather strong one pair with the rather weak one.

Example 1:

Input: 2
Output: (1,2)
Explanation:
Initially, we have the team 1 and the team 2, placed like: 1,2.
Then we pair the team (1,2) together with '(', ')' and ',', which is the final answer.

Example 2:

Input: 4
Output: ((1,4),(2,3))
Explanation:
In the first round, we pair the team 1 and 4, the team 2 and 3 together, as we need to make the strong team and weak team together.
And we got (1,4),(2,3).
In the second round, the winners of (1,4) and (2,3) need to play again to generate the final winner, so you need to add the paratheses outside them.
And we got the final answer ((1,4),(2,3)).

Example 3:

Input: 8
Output: (((1,8),(4,5)),((2,7),(3,6)))
Explanation:
First round: (1,8),(2,7),(3,6),(4,5)
Second round: ((1,8),(4,5)),((2,7),(3,6))
Third round: (((1,8),(4,5)),((2,7),(3,6)))
Since the third round will generate the final winner, you need to output the answer (((1,8),(4,5)),((2,7),(3,6))). 

Note:

  1. The n is in range [2, 212].
  2. We ensure that the input n can be converted into the form 2k, where k is a positive integer.

有n只队伍(n的范围[2, 212], 正偶数),编号为1 ~ n,队伍按照最强和最弱的分在一组的原则分组比赛,给出一直到最后一轮比赛的分组方法。

解法1:迭代iterative,

解法2:递归recursive,

Java:

public String findContestMatch(int n) {
List<String> matches = new ArrayList<>();
for(int i = 1; i <= n; i++) matches.add(String.valueOf(i)); while(matches.size() != 1){
List<String> newRound = new ArrayList<>();
for(int i = 0; i < matches.size()/2; i++)
newRound.add("(" + matches.get(i) + "," + matches.get(matches.size() - i - 1) + ")");
matches = newRound;
}
return matches.get(0);
}

Java:

 public String findContestMatch(int n) {
String[] m = new String[n];
for (int i = 0; i < n; i++) {
m[i] = String.valueOf(i + 1);
} while (n > 1) {
for (int i = 0; i < n / 2; i++) {
m[i] = "(" + m[i] + "," + m[n - 1 - i] + ")";
}
n /= 2;
} return m[0];
}

Java: LinkedList  

public String findContestMatch(int n) {
LinkedList<String> res = new LinkedList<>(); for (int i = 1; i <= n; i++) res.add(i + ""); while (res.size() > 1) {
LinkedList<String> tmp = new LinkedList<>(); while (!res.isEmpty()) {
tmp.add("(" + res.remove(0) + "," + res.remove(res.size() - 1) + ")");
} res = tmp;
} return res.get(0);
}

Java:

public string FindContestMatch(int n) {
string[] arr = new string[n];
for (int i = 0; i < n; i++) arr[i] = (i + 1).ToString(); int left = 0;
int right = n - 1;
while (left < right)
{
while (left < right)
{
arr[left] = "(" + arr[left] + "," + arr[right] + ")";
left++;
right--;
}
left = 0;
} return arr[0];
} 

Python:

# Time:  O(n)
# Space: O(n)
class Solution(object):
def findContestMatch(self, n):
"""
:type n: int
:rtype: str
"""
matches = map(str, range(1, n+1))
while len(matches)/2:
matches = ["({},{})".format(matches[i], matches[-i-1]) for i in xrange(len(matches)/2)]
return matches[0]

Python:

class Solution(object):
def solve(self, groups):
size = len(groups)
if size == 1: return groups[0]
ngroups = []
for x in range(size / 2):
ngroups.append('(' + groups[x] + ',' + groups[size - x - 1] + ')')
return self.solve(ngroups) def findContestMatch(self, n):
"""
:type n: int
:rtype: str
"""
return self.solve(map(str, range(1, n + 1)))

Python: wo

class Solution():
def contestMatches(self, n):
s = []
for i in xrange(n):
s.append(str(i + 1))
while n > 1:
cur = []
for m in xrange(len(s) / 2):
cur.append((s[m], s[len(s) - 1 - m]))
s = cur
n /= 2 return s[0]   

Python: wo

class Solution():
def contestMatches(self, n):
s = []
for i in xrange(n):
s.append(str(i + 1)) return self.helper(s) def helper(self, s):
if len(s) == 1:
return s[0]
curr = []
i, j = 0, len(s) - 1
while i < j:
curr.append((s[i], s[j]))
i += 1
j -= 1
return self.helper(curr)  

C++:

// Time:  O(n)
// Space: O(n)
class Solution {
public:
string findContestMatch(int n) {
vector<string> matches(n);
for (int i = 0; i < n; ++i) {
matches[i] = to_string(i + 1);
}
while (matches.size() / 2) {
vector<string> next_matches;
for (int i = 0; i < matches.size() / 2; ++i) {
next_matches.emplace_back("(" + matches[i] + "," + matches[matches.size() - 1 - i] + ")");
}
swap(matches, next_matches);
}
return matches[0];
}
};

C++:

class Solution {
public:
string findContestMatch(int n) {
vector<string> v;
for (int i = 1; i <= n; ++i) v.push_back(to_string(i));
while (n > 1) {
for (int i = 0; i < n / 2; ++i) {
v[i] = "(" + v[i] + "," + v[n - i - 1] + ")";
}
n /= 2;
}
return v[0];
}
};

C++:

class Solution {
public:
string findContestMatch(int n) {
vector<string> v;
for (int i = 1; i <= n; ++i) v.push_back(to_string(i));
helper(n, v);
return v[0];
}
void helper(int n, vector<string>& v) {
if (n == 1) return;
for (int i = 0; i < n; ++i) {
v[i] = "(" + v[i] + "," + v[n - i - 1] + ")";
}
helper(n / 2, v);
}
};

  

  

All LeetCode Questions List 题目汇总

最新文章

  1. ASP.NET MVC——URL路由
  2. Redis集群(九):Redis Sharding集群Redis节点主从切换后客户端自动重新连接
  3. 超好用的plsql设置
  4. git 学习笔记6--remote &amp; log
  5. xcode插件XAlign
  6. Orchard用LiveWriter写博客
  7. 利用utl_file来读取文件.
  8. Java同步块
  9. nump中的为随机数产生器的seed
  10. 64位操作系统下用Microsoft.Jet.OLEDB.4.0出现未注册错误
  11. input file样式修改,图片预览删除功能
  12. Android4.4.2KK竖屏强制更改为横屏的初步简略方案
  13. 前端学习总结(一)——常见数据结构的javascript实现
  14. vm12 安装ubuntu15.10详细图文教程 虚拟机安装ubuntu安装 ubuntu更新软件 ubuntu一直卡在下载语言怎么办?
  15. Java线程池不错的总结博客
  16. [CF960G] Bandit Blues
  17. 记录参加QCon2017北京站的心得
  18. ThinkPHP3.2.3中使用smarty模板引擎循环
  19. Oracle 最新版本变化 转帖
  20. 1.Two Sum (Array; HashTable)

热门文章

  1. python测试开发django-58.MySQL server has gone away错误的解决办法
  2. requireJS的基本使用
  3. CentOS 7.5下KVM的安装与配置
  4. http消息与webservice
  5. ARTS-week4
  6. 4、NameNode启动过程详解
  7. LeetCode 958. Check Completeness of a Binary Tree
  8. api的url规则设计,带参数的路由
  9. 洛谷 P3376 【模板】网络最大流 题解
  10. python中序列的操作