hdu

#include<bits/stdc++.h>
using namespace std;
int n,m,ans;
char s[5005];
void doit(int l,int r)
{
    int d=0,nw=0;
    for(;l<r;l++,r--)
    {
        while(l+d<r-d&&nw+abs(s[l+d]-s[r-d])<=m)nw+=abs(s[l+d]-s[r-d]),d++;
        ans=max(ans,d);
        nw-=abs(s[l]-s[r]);
        d--;
    }
}
void sol()
{
    scanf("%d%s",&m,s);
    n=strlen(s);
    ans=0;
    for(int i=n-1;i>=1;i--)doit(0,i);
    for(int i=1;i<n-1;i++)doit(i,n-1);
    printf("%d\n",ans);
}
int main()
{
    int tt;scanf("%d",&tt);
    while(tt--)sol();
    return 0;
}

#include<bits/stdc++.h>
using namespace std;
int n,cc,cs,cnt[200005],vis[200005],c[200005],sz[200005];
long long ans,res;
vector<int>g[200005];
void dfs(int x,int p)
{
    sz[x]=1;
    int ss=0;
    for(int i=0;i<g[x].size();i++)if(g[x][i]!=p)
    {
        int lst=cnt[c[x]];
        dfs(g[x][i],x);
        sz[x]+=sz[g[x][i]];
        int nw=cnt[c[x]]-lst;
        ss+=nw;
        nw=sz[g[x][i]]-nw;
        res+=1ll*nw*(nw-1)/2;
    }
    cnt[c[x]]+=sz[x]-ss;
}
void sol()
{
    cc=0;
    memset(vis,0,sizeof(vis));
    memset(cnt,0,sizeof(cnt));
    for(int i=1;i<=n;i++)scanf("%d",&c[i]),vis[c[i]]=1;
    for(int i=1;i<=n;i++)if(vis[i])cc++;
    for(int i=1;i<=n;i++)g[i].clear();
    for(int i=1;i<n;i++){int u,v;scanf("%d%d",&u,&v);g[u].push_back(v);g[v].push_back(u);}
    res=0;
    dfs(1,0);
    ans=1ll*n*(n-1)/2*cc;
    for(int i=1;i<=n;i++)if(vis[i])
    {
        int sz=n-cnt[i];
        res+=1ll*sz*(sz-1)/2;
    }
    ans-=res;
    printf("Case #%d: %lld\n",++cs,ans);
}
int main()
{
    while(scanf("%d",&n)==1)sol();
    return 0;
}

#include<bits/stdc++.h>
using namespace std;
long long k,a,b,c,dd,d[5][600005];
vector<pair<long long,int> >g[5];
void sol()
{
    scanf("%lld%lld%lld%lld%lld",&k,&a,&b,&c,&dd);
    long long w=2*min(a,b);
    for(int i=1;i<=4;i++)g[i].clear();
    g[1].push_back(make_pair(2,a));
    g[2].push_back(make_pair(1,a));
    g[2].push_back(make_pair(3,b));
    g[3].push_back(make_pair(2,b));
    g[3].push_back(make_pair(4,c));
    g[4].push_back(make_pair(3,c));
    g[4].push_back(make_pair(1,dd));
    g[1].push_back(make_pair(4,dd));
    memset(d,0x3f,sizeof(d));
    d[2][0]=0;
    queue<pair<int,int> >q;
    q.push(make_pair(0,2));
    while(!q.empty())
    {
        long long l=q.front().first,x=q.front().second;
        q.pop();
        for(int i=0;i<2;i++)if(d[g[x][i].first][(l+g[x][i].second)%w]>l+g[x][i].second)
        {
            d[g[x][i].first][(l+g[x][i].second)%w]=l+g[x][i].second;
            q.push(make_pair(l+g[x][i].second,g[x][i].first));
        }
    }
    long long ans=2e18;
    for(int i=0;i<w;i++)if(d[2][i]>k)ans=min(ans,d[2][i]);else ans=min(ans,d[2][i]+(k-d[2][i]+w-1)/w*w);
    printf("%lld\n",ans);
}
int main()
{
    int tt;cin>>tt;
    while(tt--)sol();
    return 0;
}

#include<bits/stdc++.h>
using namespace std;
const int md=998244353;
int n,vis[600005];
vector<pair<int,int> >g[600005];
vector<int>e,t;
void sol()
{
    scanf("%d",&n);
    for(int i=1;i<=n*2;i++)vis[i]=0,g[i].clear();
    for(int i=1;i<=n;i++)
    {
        int u,wu,v,wv;
        scanf("%d%d%d%d",&u,&wu,&v,&wv);
        g[i].push_back(make_pair(n+u,wu));
        g[n+u].push_back(make_pair(i,wu));
        g[i].push_back(make_pair(n+v,wv));
        g[n+v].push_back(make_pair(i,wv));
    }
    bool f=false;
    for(int i=1;i<=n;i++)if(!g[n+i].size())f=true;
    if(f){printf("0\n");return;}
    int ans=1;
    for(int i=n+1;i<=2*n;i++)if(g[i].size()==1&&!vis[i])
    {
        int res=g[i][0].second,lst=i,nw=g[i][0].first;
        while(true)
        {
            vis[lst]=1;vis[nw]=1;
            int nxt=g[nw][0].first+g[nw][1].first-lst;
            if(g[nxt].size()==1)res=0;
            if(g[nxt].size()!=2)
            {
                int j;
                for(j=0;j<g[nxt].size();j++)if(g[nxt][j].first==nw)break;
                g[nxt].erase(g[nxt].begin()+j);
                break;
            }
            lst=nxt;
            nw=g[nxt][0].first+g[nxt][1].first-nw;
            int cc=(g[lst][0].first==nw)?g[lst][0].second:g[lst][1].second;
            res=1ll*res*cc%md;
        }
        ans=1ll*ans*res%md;
    }
    for(int i=1;i<=2*n;i++)if(g[i].size()==2&&!vis[i])
    {
        e.clear();t.clear();
        e.push_back(i);e.push_back(g[i][0].first);
        t.push_back(g[i][0].second);
        int lst=i,nw=g[i][0].first;
        vis[lst]=1;
        while(true)
        {
            vis[nw]=1;
            int nxt=g[nw][0].first+g[nw][1].first-lst;
            int cc=(g[nw][0].first==nxt)?g[nw][0].second:g[nw][1].second;
            t.push_back(cc);
            if(vis[nxt])break;
            lst=nw;nw=nxt;e.push_back(nw);
        }
        int res1=1,res2=1;
        for(int i=0;i<t.size();i+=2)res1=1ll*res1*t[i]%md;
        for(int i=1;i<t.size();i+=2)res2=1ll*res2*t[i]%md;
        res1=(res1+res2)%md;
        ans=1ll*ans*res1%md;
    }
    printf("%d\n",ans);
}
int main()
{
    int tt;scanf("%d",&tt);
    while(tt--)sol();
    return 0;
}

#include<bits/stdc++.h>
using namespace std;
const double eps=1e-6;
struct st{double mn,tg;}seg[240005];
int n,a[60005],ps[60005];
void up(int x){seg[x].mn=min(seg[x<<1].mn,seg[x<<1|1].mn);}
void down(int x)
{
    seg[x<<1].mn+=seg[x].tg;
    seg[x<<1].tg+=seg[x].tg;
    seg[x<<1|1].mn+=seg[x].tg;
    seg[x<<1|1].tg+=seg[x].tg;
    seg[x].tg=0;
}
void build(int x,int l,int r)
{
    seg[x]=(st){0,0};
    if(l==r)return;
    int md=l+r>>1;build(x<<1,l,md);build(x<<1|1,md+1,r);
}
void modify(int x,int l,int r,int tl,int tr,double v)
{
    if(tl<=l&&r<=tr){seg[x].mn+=v,seg[x].tg+=v;return;}
    if(seg[x].tg)down(x);
    int md=l+r>>1;
    if(tl<=md)modify(x<<1,l,md,tl,tr,v);
    if(tr>md)modify(x<<1|1,md+1,r,tl,tr,v);
    up(x);
}
double query(int x,int l,int r,int tl,int tr)
{
    if(tl<=l&&r<=tr)return seg[x].mn;
    if(seg[x].tg)down(x);
    int md=l+r>>1;double ans=1e9;
    if(tl<=md)ans=min(ans,query(x<<1,l,md,tl,tr));
    if(tr>md)ans=min(ans,query(x<<1|1,md+1,r,tl,tr));
    return ans;
}
bool chk(double x)
{
    build(1,1,n);
    memset(ps,0,sizeof(ps));
    for(int i=1;i<=n;i++)
    {
        modify(1,1,n,ps[a[i]]+1,i,1);
        modify(1,1,n,1,i,-x);
        if(query(1,1,n,1,i)<=0)return true;
        ps[a[i]]=i;
    }
    return false;
}
int main()
{
    int tt;scanf("%d",&tt);
    while(tt--)
    {
        scanf("%d",&n);
        for(int i=1;i<=n;i++)scanf("%d",&a[i]);
        double l=0,r=1,ans=1;
        while(r-l>=eps)
        {
            double md=(l+r)/2.0;
            if(chk(md))ans=md,r=md;else l=md;
        }
        printf("%.6f\n",ans);
    }
    return 0;
}

#include<bits/stdc++.h>
using namespace std;
const long long md=998244353ll;
int n,m,a[2005],b[2005];
long long dp[2][2005];
void sol()
{
    scanf("%d%d",&n,&m);
    for(int i=0;i<n;i++)scanf("%d",&a[i]);
    for(int i=0;i<m;i++)scanf("%d",&b[i]);
    long long ans=0;
    memset(dp,0,sizeof(dp)); 
    for(int i=0;i<n;i++)
    {
        long long s1=0,s2=0;//·?￡?1è 
        for(int j=0;j<m;j++)
        {
            if(a[i]>b[j])dp[0][j]=(dp[0][j]+s1)%md;
            else if(a[i]<b[j])dp[1][j]=(dp[1][j]+s2)%md;
            else
            {
                s1=(s1+dp[1][j])%md;
                s2=(s2+dp[0][j]+1)%md;
            }
        }
        ans=(ans+s1+s2)%md;
    }
    printf("%lld\n",ans);
}
int main()
{
    int tt;scanf("%d",&tt);
    while(tt--)sol();
    return 0;
}