Codeforces Round 496

感谢上天让我碰到了div 3

#include <bits/stdc++.h>
using namespace std;
#define LOCAL freopen("in","r",stdin);\
                freopen("out","w",stdout);
#define DBG2(x,y) cout<<(#x)<<"\t"<<x<<(#y)<<"\t"<<y<<endl;
int n,t,fnum,ts;
vector<int> v;

int main()
{
    LOCAL
    cin>>n;
    for(int i=1;i<=n;i++)
    {    

        cin>>t;
        if((t==fnum)&&(t==1)) v.push_back(fnum);
         if(t<fnum) v.push_back(fnum);
        fnum = t;
    }
    v.push_back(fnum);
    cout<<v.size()<<endl;
    for(int i=0;i<v.size();i++)
        cout<<v[i]<< " ";

}

#include<bits/stdc++.h>
using namespace std;
#define LOACL  freopen("in","r",stdin);\
         freopen("out","w",stdout); 
 
int main()
{
    LOACL
     string a,b;
     cin>>a>>b;
     int lena = a.length() ,lenb = b.length();
     int s=0;
     for(int i=lena-1,j=lenb-1;i>=0&&j>=0;i--,j--)
     {
          if(a[i]==b[j]) s++;
          else break;
     }
     cout<<lena+lenb-2*s<<endl;
} 

#include<bits/stdc++.h>
using namespace std;
#define LOACL  freopen("in","r",stdin);\
         freopen("out","w",stdout);  
#define DBG(x) cout<<(#x)<<"="<<x<<endl
#define DBG2(x,y) cout<<(#x)<<"="<<x<<"\t"<<(#y)<<"="<<y<<endl
#define DBG3(x,y,z) cout<<(#x)<<"="<<x<<"\t"<<(#y)<<"="<<y<<"\t"<<(#z)<<"="<<z<<endl

int main()
{
    LOACL 
    int n,t,num=0;
    map<int,int> m ;
    cin>>n;
    for(int i=0;i<n;i++)
    { 
        cin>>t;
        m[t]++;
    }
       map<int,int>::iterator it  = m.begin();
       for(;it!=m.end();it++)
       {
           if((*it).second==0)continue;
           bool flag = false;
           for(int j=0;j<=31;j++)
        {
            int s = 1<<j;
            int k = (*it).first;
            if(k>s) continue; 
            if(s-k == k && m[k]>=2)
            {
            //    DBG3(s,k,"a");
                flag = true;
                break;
            }
            else if(s-k!=k&& m[s-k]>0)
            {

            //    DBG3(s,k,"b");
                flag = true;
                break;
            }
        }
        if(!flag) num+=(*it).second;
        //DBG3((*it).first,flag,num);
        
       }
       cout<<num<<endl;
    
}

#include<bits/stdc++.h>
using namespace std;
#define LOACL  freopen("in","r",stdin);\
         freopen("out","w",stdout); 
 
#define DBG(x) cout<<(#x)<<"="<<x<<endl
#define DBG2(x,y) cout<<(#x)<<"="<<x<<"\t"<<(#y)<<"="<<y<<endl
#define DBG3(x,y,z) cout<<(#x)<<"="<<x<<"\t"<<(#y)<<"="<<y<<"\t"<<(#z)<<"="<<z<<endl
 

int main()
{
    LOACL
    string str;
    cin>>str;
    int bnum=0,num=0;
    vector<int> v;
    for(int i=str.length()-1;i>=0;i--)
    {
        int tmp = str[i]-'0';
        if(tmp%3==0)
        {
            //DBG(tmp);
            num++;v.clear();
        //    cout<<v.size();
        }
        else 
        {
            bool flag = false;
            int v_size = v.size();
            for(int i=0;i<v_size;i++)
            {
                int k = tmp*10+v[i];
                if(k%3==0)
                {
                //    DBG(k);
                    num++;v.clear();
                    flag =  true;
                    break;
                }
                else
                {
                    v[i] = k;
                }
            }
            if(flag) continue;
            v.push_back(tmp);
        }
    }
    cout<<num<<endl;
}

E 题目，感谢Q神的思路 ，维护一个游标，处理好区间位数为m 和区间中位数为m-1 做差值。

#include<bits/stdc++.h>
using namespace std;
#define LOACL  freopen("in","r",stdin);\
         freopen("out","w",stdout); 
 
#define DBG(x) cout<<(#x)<<"="<<x<<endl
#define DBG2(x,y) cout<<(#x)<<"="<<x<<"\t"<<(#y)<<"="<<y<<endl
#define DBG3(x,y,z) cout<<(#x)<<"="<<x<<"\t"<<(#y)<<"="<<y<<"\t"<<(#z)<<"="<<z<<endl

const int sz = (int)2e5+10;
typedef long long ll;
ll c[sz*2],a[sz],b[sz],n,m,cur,sum,i,j ;
ll ss(int m ,ll res = 0)
{
     
    #if 1 
    sum = 0; cur = n+1; 
    memset(c,0,sizeof(c)); c[cur] =1;
    for(int i  =1 ;i<=n;i++)
    {
        if(a[i]<=m) sum+=c[++cur];
        else sum-=c[cur--];
        res+=sum;
        c[cur]++; 
    }
     
    return res;
    #endif
     

}
int main()
{
    LOACL
    cin>>n>>m;
    for(int i=1;i<=n;i++) cin>>a[i];
    cout<<ss(m)-ss(m-1)<<endl;    
}

#include<bits/stdc++.h>
using namespace std;
#define LOACL  freopen("in","r",stdin);\
         freopen("out","w",stdout); 
const int sz = (int)2e5+10; 
int n,m,k,u,v,dist[sz];
string res;
vector<string> ans;
vector<int> g[sz],num[sz],ids[sz];

void bfs()
{
    memset(dist,-1,sizeof(dist));

    queue<int> q;
    q.push(1);
    dist[1]=0;
    while(!q.empty())
    {
        int v = q.front();
        q.pop();
        int n_size = g[v].size();
        for(int i=0;i<n_size;i++)
        {
            int to  = g[v][i];
            if(dist[to]==-1)
            {
                dist[to] = dist[v]+1;
                q.push(to);
            }
            if(dist[to]==dist[v]+1)
            {
                ids[to].push_back(num[v][i]);
            }
        }
    }
}
void write()
{
    cout<<ans.size()<<endl;
    for(int i=0;i<ans.size();i++)
    {
        cout<<ans[i].c_str()<<endl;
    }
    exit(0);
}
void rec(int v)
{
    if(v==n+1)
    {
        ans.push_back(res);
        if(ans.size()==k)write();
        return ;
    }

    int ids_size = ids[v].size();
    for(int i=0;i<ids_size;i++)
    {    
        int id = ids[v][i];
        res[id]='1';
        rec(v+1);
        res[id]='0';

    }
}
int main()
{
    LOACL
    cin>>n>>m>>k;
    for(int i=0;i<m;i++)
    {
        cin>>u>>v;
        g[u].push_back(v);
        g[v].push_back(u);
        num[u].push_back(i);
        num[v].push_back(i); 
        res+='0';
    }
    bfs();
    rec(2);
    write(); 
}