一本通1583叶子的染色

#include <bits/stdc++.h>
using namespace std;
inline int read()
{
    int s=0;
    bool f=0;
    char ch=‘ ‘;
    while(!isdigit(ch))
    {
        f|=(ch==‘-‘);
        ch=getchar();
    }
    while(isdigit(ch))
    {
        s=(s<<3)+(s<<1)+(ch^48);
        ch=getchar();
    }
    return (f)?(-s):(s);
}
#define R(x) x=read()
inline void write(long long x)
{
    if(x<0)
    {
        putchar(‘-‘);
        x=-x;
    }
    if(x<10)
    {
        putchar(x+‘0‘);
        return;
    }
    write(x/10);
    putchar((x%10)+‘0‘);
    return;
}
inline void writeln(long long x)
{
    write(x);
    putchar(‘\n‘);
    return;
}
#define W(x) write(x),putchar(‘ ‘)
#define Wl(x) writeln(x)
const int N=10005,B=5025,M=20005,inf=0x3f3f3f3f;
int n,m,Cor[B];
struct Tree
{
    int tot,Next[M],to[M],head[N];
    inline void add(int x,int y)
    {
        Next[++tot]=head[x];
        to[tot]=y;
        head[x]=tot;
        return;
    }
    long long dp[N][2];
    inline void dfs(int x,int fa)
    {
        dp[x][0]=dp[x][1]=1;
        if(x<=m)
        {
            dp[x][Cor[x]^1]=inf;
            return;
        }
        int i;
        for(i=head[x];i;i=Next[i]) if(to[i]!=fa)
        {
            dfs(to[i],x);
            dp[x][0]+=min(dp[to[i]][0]-1,dp[to[i]][1]);
            dp[x][1]+=min(dp[to[i]][1]-1,dp[to[i]][0]);
        }
        return;
    }
    inline void Solve()
    {
        dfs(n,0);
        Wl(min(dp[n][0],dp[n][1]));
        return;
    }
    inline void Init()
    {
        tot=0;
        memset(head,0,sizeof head);
        return;
    }
}T;
int main()
{
//    freopen("9.in","r",stdin);
    int i;
    T.Init();
    R(n); R(m);
    for(i=1;i<=m;i++) R(Cor[i]);
    for(i=1;i<n;i++)
    {
        int x=read(),y=read();
        T.add(x,y); T.add(y,x);
    }
    T.Solve();
    return 0;
}
/*
input
5 3
0
1
0
1 4
2 5
4 5
3 5
output
2
*/