洛谷mNOIP模拟赛Day2-将军令

 1 #include<cstdio>
 2 #include<cstdlib>
 3 #include<algorithm>
 4 #include<cstring>
 5 #include<cmath>
 6 #include<map>
 7 #include<set>
 8 #include<queue>
 9 #include<vector>
10 #define INF 0x7f7f7f7f
11 #define pii pair<int,int>
12 #define ll long long
13 #define MAXN 100005
14 using namespace std;
15 int read(){
16     int x=0,f=1;char ch=getchar();
17     while(ch<‘0‘||ch>‘9‘){if(‘-‘==ch)f=-1;ch=getchar();}
18     while(ch>=‘0‘&&ch<=‘9‘){x=x*10+ch-‘0‘;ch=getchar();}
19     return x*f;
20 }
21 int n,k;
22 int first[MAXN],nxt[MAXN<<1],to[MAXN<<1],cnt;
23 //double edge
24 int dep[MAXN],fa[MAXN];
25 pii tmp[MAXN];
26 int b[MAXN];
27 
28 void add(int x,int y){
29     nxt[++cnt]=first[x];first[x]=cnt;to[cnt]=y;
30     nxt[++cnt]=first[y];first[y]=cnt;to[cnt]=x;
31 }
32 void dfs(int x){
33     for(int e=first[x];e;e=nxt[e]){
34         int y=to[e];
35         if(y==fa[x]){
36             continue;
37         }
38         fa[y]=x;
39         dep[y]=dep[x]+1;
40         dfs(y);
41     }
42 }
43 void solve(int x,int fa,int d){
44     if(!d){
45         return ;
46     }
47     for(int e=first[x];e;e=nxt[e]){
48         int y=to[e];
49         if(y==fa){
50             continue;
51         }
52         b[y]=1;
53         solve(y,x,d-1);
54     }
55 }
56 bool comp(const pii &p1,const pii &p2){
57     return (p1.first>p2.first);
58 }
59 int main()
60 {
61 //    freopen("general2.in","r",stdin);
62     n=read();k=read();
63     int t=read();
64     for(int i=1;i<n;i++){
65         int x=read(),y=read();
66         add(x,y);
67     }
68     dep[1]=1;dfs(1);
69     for(int i=1;i<=n;i++){
70         tmp[i]=make_pair(dep[i],i);
71     }
72     sort(tmp+1,tmp+n+1,comp);
73     int ans=0;
74     for(int i=1;i<=n;i++){
75         int t=tmp[i].second;
76         if(!b[t]){
77             int x=t;
78             for(int j=1;j<=k&&fa[x];j++){
79                 x=fa[x];
80             }
81             b[x]=1;
82             solve(x,-1,k);        
83             ans++;
84         }
85     }
86     printf("%d\n",ans);
87     return 0;
88 }