Codeforces Beta Round #79 (Div. 2 Only)

Codeforces Beta Round #79 (Div. 2 Only)

http://codeforces.com/contest/102

A

 #include<bits/stdc++.h>
 using namespace std;
 #define lson l,mid,rt<<1
 #define rson mid+1,r,rt<<1|1
 #define sqr(x) ((x)*(x))
 #define pb push_back
 #define eb emplace_back
 #define maxn 13000005
 #define eps 1e-8
 #define pi acos(-1.0)
 #define rep(k,i,j) for(int k=i;k<j;k++)
 typedef long long ll;
 typedef pair<int,int> pii;
 typedef pair<long long,int>pli;
 typedef pair<char,int> pci;
 typedef pair<pair<int,string>,pii> ppp;
 typedef unsigned long long ull;
 const long long MOD=1e9+;
 /*#ifndef ONLINE_JUDGE
         freopen("1.txt","r",stdin);
 #endif */

 int a[][];
 int v[];

 int main(){
     #ifndef ONLINE_JUDGE
      //   freopen("1.txt","r",stdin);
     #endif
     std::ios::sync_with_stdio(false);
     int n,m;
     cin>>n>>m;
     for(int i=;i<=n;i++) cin>>v[i];
     int uu,vv;
     for(int i=;i<=m;i++){
         cin>>uu>>vv;
         a[uu][vv]=a[vv][uu]=;
     }
     int ans=0x3f3f3f3f;
     for(int i=;i<=n;i++){
         for(int j=;j<=n;j++){
             for(int k=;k<=n;k++){
                 if(i==j||j==k||k==i) continue;
                 if(a[i][j]==a[j][k]&&a[j][k]==a[k][i]&&a[k][i]==){

                     ans=min(ans,v[i]+v[j]+v[k]);
                 }
             }
         }
     }
     if(ans==0x3f3f3f3f) cout<<-;
     else
     cout<<ans<<endl;
 }

B

暴力

 #include<bits/stdc++.h>
 using namespace std;
 #define lson l,mid,rt<<1
 #define rson mid+1,r,rt<<1|1
 #define sqr(x) ((x)*(x))
 #define pb push_back
 #define eb emplace_back
 #define maxn 13000005
 #define eps 1e-8
 #define pi acos(-1.0)
 #define rep(k,i,j) for(int k=i;k<j;k++)
 typedef long long ll;
 typedef pair<int,int> pii;
 typedef pair<long long,int>pli;
 typedef pair<char,int> pci;
 typedef pair<pair<int,string>,pii> ppp;
 typedef unsigned long long ull;
 const long long MOD=1e9+;
 /*#ifndef ONLINE_JUDGE
         freopen("1.txt","r",stdin);
 #endif */

 int main(){
     #ifndef ONLINE_JUDGE
      //   freopen("1.txt","r",stdin);
     #endif
     std::ios::sync_with_stdio(false);
     string str;
     cin>>str;
     int ans=;
     while(str.length()!=){
         int tmp=;
         for(int i=;i<str.length();i++) tmp+=str[i]-'';
         ans++;
         str=to_string(tmp);
     }
     cout<<ans<<endl;
 }

C

贪心

 #include<bits/stdc++.h>
 using namespace std;
 #define lson l,mid,rt<<1
 #define rson mid+1,r,rt<<1|1
 #define sqr(x) ((x)*(x))
 #define pb push_back
 #define eb emplace_back
 #define maxn 13000005
 #define eps 1e-8
 #define pi acos(-1.0)
 #define rep(k,i,j) for(int k=i;k<j;k++)
 typedef long long ll;
 typedef pair<int,int> pii;
 typedef pair<long long,int>pli;
 typedef pair<int,char> pic;
 typedef pair<pair<int,string>,pii> ppp;
 typedef unsigned long long ull;
 const long long MOD=1e9+;
 /*#ifndef ONLINE_JUDGE
         freopen("1.txt","r",stdin);
 #endif */

 int book[];

 int main(){
     #ifndef ONLINE_JUDGE
      //   freopen("1.txt","r",stdin);
     #endif
     std::ios::sync_with_stdio(false);
     string str;
     int n;
     cin>>str>>n;
     for(int i=;i<str.length();i++){
         book[str[i]-'a']++;
     }
     if(str.length()<=n) cout<<<<endl<<endl;
     else{
         set<char>se;
         vector<pic>ve;
         for(int i=;i<;i++){
             ve.pb({book[i],'a'+i});
         }
         sort(ve.begin(),ve.end());
         for(int i=;i<ve.size();i++){
             if(ve[i].first<=n){
                 n-=ve[i].first;
                 se.insert(ve[i].second);
             }
             else{
                 break;
             }
         }
         string s="";
         for(int i=;i<str.length();i++){
             if(se.count(str[i])) continue;
             else s+=str[i];
         }
         set<char>ss;
         for(int i=;i<s.length();i++){
             ss.insert(s[i]);
         }
         cout<<ss.size()<<endl<<s<<endl;
     }
 }

D

树状数组+离散化

 #include<bits/stdc++.h>
 using namespace std;
 #define lson l,mid,rt<<1
 #define rson mid+1,r,rt<<1|1
 #define sqr(x) ((x)*(x))
 #define pb push_back
 #define eb emplace_back
 #define maxn 13000005
 #define eps 1e-8
 #define pi acos(-1.0)
 #define rep(k,i,j) for(int k=i;k<j;k++)
 typedef long long ll;
 typedef pair<int,int> pii;
 typedef pair<long long,int>pli;
 typedef pair<int,char> pic;
 typedef pair<pair<int,string>,pii> ppp;
 typedef unsigned long long ull;
 const long long MOD=1e9+;
 /*#ifndef ONLINE_JUDGE
         freopen("1.txt","r",stdin);
 #endif */

 int n,m;

 map<int,int>tree;

 int lowbit(int x){
     return x&(-x);
 }

 void add(int x,int v){
     while(x<=n+){
         tree[x]=(tree[x]+v)%MOD;
         x+=lowbit(x);
     }
 }

 int getsum(int x){
     int ans=;
     while(x){
         ans=(ans+tree[x])%MOD;
         x-=lowbit(x);
     }
     return ans;
 }
 vector<pii>ve;

 int main(){
     #ifndef ONLINE_JUDGE
      //   freopen("1.txt","r",stdin);
     #endif
     std::ios::sync_with_stdio(false);
     cin>>n>>m;
     int a,b;
     for(int i=;i<=m;i++){
         cin>>a>>b;
         ve.pb({b+,a+});
     }
     sort(ve.begin(),ve.end());
     add(,);
     for(int i=;i<m;i++){
         int s=ve[i].second,t=ve[i].first;
         int tmp=getsum(t-)-getsum(s-);
         tmp=(tmp%MOD+MOD)%MOD;
         add(t,tmp);
     }
     int ans=getsum(n+)-getsum(n);
     cout<<(ans%MOD+MOD)%MOD<<endl;
 }