Leetcode-5199 Smallest String With Swaps(交换字符串中的元素)

 1 #define _for(i,a,b) for(int i = (a);i < b;i ++)
 2 #define _rep(i,a,b) for(int i = (a);i > b;i --)
 3 #define INF 0x3f3f3f3f
 4 #define MOD 1000000007
 5 #define pb push_back
 6 #define maxn 100003
 7 
 8 int par[maxn]; //父亲
 9 int high[maxn]; //树的高度
10 
11 void init(int n)
12 {
13     _for(i,0,n)
14     {
15         par[i] = i;
16         high[i] = 0;
17     }
18 }
19 
20 int find(int x)
21 {
22     return par[x] == x ? x : par[x] = find(par[x]);
23 }
24 
25 void unite(int x,int y)
26 {
27     x = find(x);
28     y = find(y);
29     if(x==y) return ;
30 
31     if(high[x]<high[y])
32         par[x] = y;
33     else
34     {
35         par[y] = x;
36         if(high[x]==high[y])
37             high[x] ++;
38     }
39 }
40 
41 bool same(int x,int y)
42 {
43     return find(x) == find(y);
44 }
45 
46 class Solution
47 {
48     vector<int> a[maxn];
49     public:
50         string smallestStringWithSwaps(string s, vector<vector<int>>& pairs)
51         {
52             int n = s.size();
53             string rnt = s;
54             init(n);
55             _for(i,0,pairs.size())
56                 unite(pairs[i][0],pairs[i][1]);
57             
58             _for(i,0,s.size())
59                 a[find(i)].pb(i);
60             
61             _for(i,0,n)
62             {
63                 string tmp;
64                 _for(j,0,a[i].size())
65                     tmp += s[a[i][j]];
66                 sort(tmp.begin(),tmp.end());
67                 _for(j,0,a[i].size())
68                     rnt[a[i][j]] = tmp[j];
69             }
70             return rnt;
71         }
72 };