连这种题都wa,这几天是肿么了!!!!
#include<iostream>
#include<vector>
#include<algorithm>
#include<cstdio>
#include<queue>
#include<stack>
#include<string>
#include<map>
#include<set>
#include<cmath>
#include<cassert>
#include<cstring>
#include<iomanip>
using namespace std;
#ifdef _WIN32
#define i64 __int64
#define out64 "%I64d\n"
#define in64 "%I64d"
#else
#define i64 long long
#define out64 "%lld\n"
#define in64 "%lld"
#endif
/************ for topcoder by zz1215 *******************/
#define FOR(i,a,b) for( int i = (a) ; i <= (b) ; i ++)
#define FFF(i,a) for( int i = 0 ; i < (a) ; i ++)
#define FFD(i,a,b) for( int i = (a) ; i >= (b) ; i --)
#define S64(a) scanf(in64,&a)
#define SS(a) scanf("%d",&a)
#define LL(a) ((a)<<1)
#define RR(a) (((a)<<1)+1)
#define pb push_back
#define CL(Q) while(!Q.empty())Q.pop()
#define MM(name,what) memset(name,what,sizeof(name))
#define MAX(a,b) ((a)>(b)?(a):(b))
#define MIN(a,b) ((a)<(b)?(a):(b))
#define read freopen("out.txt","r",stdin)
#define write freopen("zz.txt","w",stdout)
const int inf = 0x3f3f3f3f;
const i64 inf64 = 0x3f3f3f3f3f3f3f3fLL;
const double oo = 10e9;
const double eps = 10e-9;
const double pi = acos(-1.0);
const int maxn = 222;
int n;
int a[maxn];
int b[maxn];
vector<int>g[maxn];
int dpy[2][maxn];
int dpn[2][maxn];
int f[maxn];
bool vis[maxn];
void df1(int now)
{
vis[now]=true;
int to;
for(int i=0;i<g[now].size();i++)
{
to = g[now][i];
if(!vis[to])
{
f[to]=now;
df1(to);
}
}
return ;
}
void df2(int now)
{
int to;
int sa=0;
int sb=0;
int ta=inf;
int tb=inf;
for(int i=0;i<g[now].size();i++)
{
to = g[now][i];
if(to!=f[now])
{
df2(to);
sa+=dpy[0][to];
sb+=dpy[1][to];
ta=MIN(ta,dpn[0][to]-dpy[0][to]);
tb=MIN(tb,dpn[1][to]-dpy[1][to]);
}
}
dpn[0][now]=a[now]+sa;
dpn[1][now]=b[now]+sb;
dpn[0][now]=MIN(dpn[0][now],ta+sa+a[now]/2);
dpn[1][now]=MIN(dpn[1][now],tb+sb+b[now]/2);
dpy[0][now]=MIN(a[now]/2+sa,dpn[1][now]);
dpy[1][now]=MIN(dpn[0][now],b[now]/2+sb);
return ;
}
int start()
{
memset(vis,false,sizeof(vis));
memset(f,-1,sizeof(f));
df1(1);
df2(1);
return MIN(dpn[0][1],dpn[1][1]);
}
int main()
{
int now,to;
while(cin>>n)
{
for(int i=1;i<=n;i++)
{
g[i].clear();
}
for(int i=1;i<=n;i++)
{
cin>>a[i];
}
for(int i=1;i<=n;i++)
{
cin>>b[i];
}
for(int i=1;i<=n-1;i++)
{
cin>>now>>to;
g[now].pb(to);
g[to].pb(now);
}
cout<<start()<<endl;
}
return 0;
}