Codeforces Round #425 (Div. 2)
A超级水，三分钟1a
#include<map>
#include<set>
#include<cmath>
#include<queue>
#include<stack>
#include<vector>
#include<cstdio>
#include<cassert>
#include<iomanip>
#include<cstdlib>
#include<cstring>
#include<iostream>
#include<algorithm>
#define C 0.5772156649
#define pi acos(-1.0)
#define ll long long
#define mod 1000000007
#define ls l,m,rt<<1
#define rs m+1,r,rt<<1|1
#pragma comment(linker, "/STACK:1024000000,1024000000")
using namespace std;
const double g=10.0,eps=1e-7;
const int N=100000+10,maxn=500+100,inf=0x3f3f3f;
int main()
{
ios::sync_with_stdio(false);
cin.tie(0);
ll a,b;
cin>>a>>b;
ll ans=a/b;
if(ans&1)cout<<"YES"<<endl;
else cout<<"NO"<<endl;
return 0;
}
/*********************
*********************/
A
B有点坑啊，我分了很多种情况考虑，最后重判还是wa了，考虑输入字符串与原来字符串的长度问题
#include<map>
#include<set>
#include<cmath>
#include<queue>
#include<stack>
#include<vector>
#include<cstdio>
#include<cassert>
#include<iomanip>
#include<cstdlib>
#include<cstring>
#include<iostream>
#include<algorithm>
#define C 0.5772156649
#define pi acos(-1.0)
#define ll long long
#define mod 1000000007
#define ls l,m,rt<<1
#define rs m+1,r,rt<<1|1
#pragma comment(linker, "/STACK:1024000000,1024000000")
using namespace std;
const double g=10.0,eps=1e-7;
const int N=100000+10,maxn=500+100,inf=0x3f3f3f;
bool good[30];
int main()
{
ios::sync_with_stdio(false);
cin.tie(0);
string s,p;
cin>>s>>p;
memset(good,0,sizeof good);
for(int i=0;i<s.size();i++)
good[s[i]-‘a‘]=1;
int k;
cin>>k;
while(k--){
string a;
cin>>a;
if(a.size()>p.size())
{
bool ok=1;
int res=a.size()-p.size(),i,j;
for(i=0,j=0;i<p.size()&&j<a.size();)
{
if(p[i]==‘?‘)
{
if(!good[a[j]-‘a‘])
{
ok=0;
break;
}
}
else if(p[i]==‘*‘)
{
for(int l=i;l<=i+res;l++)
if(good[a[l]-‘a‘])
{
ok=0;
break;
}
}
else
{
if(p[i]!=a[j])
{
// cout<<i<<" "<<j<<endl;
ok=0;
break;
}
}
if(p[i]==‘*‘)i++,j+=res+1;
else i++,j++;
}
// cout<<i<<" "<<j<<endl;
if(ok&&j==a.size())cout<<"YES"<<endl;
else cout<<"NO"<<endl;
}
else if(a.size()+1==p.size())
{
bool ok=1;
int i,j;
for(i=0,j=0;i<p.size();)
{
if(p[i]==‘?‘)
{
if(!good[a[j]-‘a‘])
{
ok=0;
break;
}
}
else if(p[i]!=‘*‘)
{
if(a[j]!=p[i])
{
ok=0;
break;
}
}
if(p[i]==‘*‘)i++;
else i++,j++;
// cout<<i<<" "<<j<<endl;
}
if(ok&&i==p.size())cout<<"YES"<<endl;
else cout<<"NO"<<endl;
}
else if(a.size()+1<p.size())
{
cout<<"NO"<<endl;
continue;
}
else
{
bool ok=1;
for(int i=0;i<p.size();i++)
{
if(p[i]==‘?‘)
{
if(!good[a[i]-‘a‘])
{
ok=0;
break;
}
}
else if(p[i]==‘*‘)
{
if(good[a[i]-‘a‘])
{
ok=0;
break;
}
}
else
{
if(a[i]!=p[i])
{
ok=0;
break;
}
}
}
if(ok)cout<<"YES"<<endl;
else cout<<"NO"<<endl;
}
}
return 0;
}
/*********************
a
ab
1
a
*********************/
C过的人很少，放弃了
D比赛的时候知道是lca，但是不会lca了（太弱了。）
先三个点求lca，找到最深的节点就是转折点，然后求转折点到三个点的最大距离+1就是答案了
#include<map>
#include<set>
#include<cmath>
#include<queue>
#include<stack>
#include<vector>
#include<cstdio>
#include<cassert>
#include<iomanip>
#include<cstdlib>
#include<cstring>
#include<iostream>
#include<algorithm>
#define C 0.5772156649
#define pi acos(-1.0)
#define ll long long
#define ull unsigned long long
#define mod 1000000007
#define ls l,m,rt<<1
#define rs m+1,r,rt<<1|1
#pragma comment(linker, "/STACK:1024000000,1024000000")
using namespace std;
const double g=10.0,eps=1e-12;
const int N=100000+10,maxn=500+100,inf=0x3f3f3f;
vector<int>v[N];
int depth[N],father[20][N];
void dfs(int u,int f,int d)
{
father[0][u]=f;
depth[u]=d;
for(int i=0;i<v[u].size();i++)
if(v[u][i]!=f)
dfs(v[u][i],u,d+1);
}
int lca(int x,int y)
{
if(depth[x]>depth[y])swap(x,y);
for(int k=0;k<20;k++)
if((depth[y]-depth[x])>>k&1)
y=father[k][y];
if(x==y)return x;
for(int k=20-1;k>=0;k--)
{
if(father[k][x]!=father[k][y])
{
x=father[k][x];
y=father[k][y];
}
}
return father[0][x];
}
int dis(int x,int y)
{
return depth[x]+depth[y]-2*depth[lca(x,y)];
}
void init(int n)
{
dfs(1,-1,0);
for(int i=1;i<20;i++)
{
for(int j=1;j<=n;j++)
{
father[i][j]=father[i-1][father[i-1][j]];
}
}
}
int main()
{
/* ios::sync_with_stdio(false);
cin.tie(0);*/
int n,q;
scanf("%d%d",&n,&q);
for(int i=1;i<=n;i++)v[i].clear();
for(int i=2;i<=n;i++)
{
int a;
scanf("%d",&a);
v[i].push_back(a);
v[a].push_back(i);
}
memset(father,-1,sizeof father);
memset(depth,0,sizeof depth);
init(n);
while(q--){
int a,b,c;
scanf("%d%d%d",&a,&b,&c);
int x=lca(a,b),y=lca(b,c),z=lca(a,c);
//cout<<x<<" "<<y<<" "<<z<<endl;
if(depth[x]<depth[y])x=y;
if(depth[x]<depth[z])x=z;
printf("%d\n",max(dis(x,a),max(dis(x,b),dis(x,c)))+1);
}
return 0;
}
/*********************
3 2
1 1
1 2 3
2 3 3
*********************/
D
时间： 2024-10-04 07:02:46