Codeforces Beta Round #35 (Div. 2)

Codeforces Beta Round #35 (Div. 2)

http://codeforces.com/contest/35

A

这场的输入输出是到文件中的，不是标准的输入输出。。。没注意看，RE了好久。。。

 #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 eps 1e-8
 #define PI acos(-1.0)
 #define maxn 1000005
 typedef long long ll;
 typedef unsigned long long ull;

 /*#ifndef ONLINE_JUDGE
         freopen("1.txt","r",stdin);
 #endif */

 ifstream cinn("input.txt");
 ofstream coutt("output.txt");

 int main(){
     #ifndef ONLINE_JUDGE
      //   freopen("1.txt","r",stdin);
     #endif
     std::ios::sync_with_stdio(false);
     int u,v;
     int b;

     int a[];
     memset(a,,sizeof(a));
     cinn>>b;
     a[b]=;
     for(int i=;i<;i++){
         cinn>>u>>v;
         swap(a[u],a[v]);
     }
     for(int i=;i<=;i++){
         if(a[i]==){
             coutt<<i;
             return ;
         }
     }
     return ;
 }

B

模拟

 #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 eps 1e-8
 #define PI acos(-1.0)
 #define maxn 1000005
 typedef long long ll;
 typedef unsigned long long ull;

 /*#ifndef ONLINE_JUDGE
         freopen("1.txt","r",stdin);
 #endif */
 string s,t,x[][];
 int n,m,k,i,j,a,b,o,r;

 int main(){
   //  #ifndef ONLINE_JUDGE
         freopen ("input.txt","r",stdin);
         freopen ("output.txt","w",stdout);
    // #endif
     cin>>n>>m>>k;
     for (o=;o<=k;o++){
         cin>>s;
         if (s[]=='+'){
             cin>>a>>b>>t;
             while (){
                 if (x[a][b]==""){
                     x[a][b]=t;
                     break;
                 }
                 else {
                     b++;
                     if (b>m){
                         a++;
                         b=;
                         if (a>n)
                             break;
                     }
                 }
             }
         }
         else {
             cin>>t;
             r=;
             for (i=;i<=n;i++){
                 if (r==)
                     break;
                 for (j=;j<=m;j++){
                     if (x[i][j]==t){
                         r=;
                         break;
                     }

                 }
             }
             if (r==){
                 cout<<-<<" "<<-<<endl;
             }
             else {
                 cout<<i-<<" "<<j<<endl;
                 x[i-][j]="";
             }
         }
     }
 }

C

bfs

 #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 eps 1e-8
 #define PI acos(-1.0)
 #define maxn 1000005
 typedef long long ll;
 typedef unsigned long long ull;

 /*#ifndef ONLINE_JUDGE
         freopen("1.txt","r",stdin);
 #endif */
 int book[][];
 int n,m,k;
 struct sair{
     int x,y,step;
 };
 int dir[][]={,,,,,-,-,};

 int main(){
   //  #ifndef ONLINE_JUDGE
         freopen ("input.txt","r",stdin);
         freopen ("output.txt","w",stdout);
    // #endif
     cin>>n>>m>>k;
     int x,y;
     queue<sair>Q;
     sair s,e;
     for(int i=;i<=k;i++){
         cin>>x>>y;
         s.x=x,s.y=y,s.step=;
         book[x][y]=;
         Q.push(s);
     }
     int last=;
     while(!Q.empty()){
         s=Q.front();
         Q.pop();
         for(int i=;i<;i++){
             e.x=s.x+dir[i][];
             e.y=s.y+dir[i][];
             if(e.x>=&&e.x<=n&&e.y>=&&e.y<=m&&!book[e.x][e.y]){
                 e.step=s.step+;
                 if(e.step>last) last=e.step;
             //    cout<<last<<endl;
                 book[e.x][e.y]=e.step;
                 Q.push(e);
             }
         }
     }
     for(int i=;i<=n;i++){
         for(int j=;j<=m;j++){
             if(book[i][j]==last){
                 cout<<i<<" "<<j<<endl;
                 return ;
             }
         }
     }
 }

D

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 eps 1e-8
 #define PI acos(-1.0)
 #define maxn 1000005
 typedef long long ll;
 typedef unsigned long long ull;

 /*#ifndef ONLINE_JUDGE
         freopen("1.txt","r",stdin);
 #endif */

 int n,x;
 int a[];

 int main(){
   //  #ifndef ONLINE_JUDGE
         freopen ("input.txt","r",stdin);
         freopen ("output.txt","w",stdout);
    // #endif
     cin>>n>>x;
     for(int i=;i<=n;i++){
         cin>>a[i];
         a[i]=a[i]*(n-i+);
     }
     sort(a+,a+n+);
     for(int i=;i<=n;i++){
         x-=a[i];
         if(x<){
             cout<<i-<<endl;
             return ;
         }

     }
     cout<<n<<endl;
 }

E

扫瞄线，可以用线段树写，不过我是用类似模拟的方法写的

 #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 eps 1e-8
 #define PI acos(-1.0)
 #define maxn 1000005
 typedef long long ll;
 typedef unsigned long long ull;

 /*#ifndef ONLINE_JUDGE
         freopen("1.txt","r",stdin);
 #endif */

 int n;
 multiset<int>ms;
 vector<pair<int,int> >ve,ans;

 int main(){
   //  #ifndef ONLINE_JUDGE
         freopen ("input.txt","r",stdin);
         freopen ("output.txt","w",stdout);
    // #endif
     std::ios::sync_with_stdio(false);
     cin>>n;
     int l,r,h;
     for(int i=;i<n;i++){
         cin>>h>>l>>r;
         ve.push_back(make_pair(l,h));
         ve.push_back(make_pair(r,-h));
     }
     sort(ve.begin(),ve.end());
     int i=,j;
     h=;
     ms.insert(h);
     while(i<ve.size()){
         j=i;
         do{
             if(ve[j].second>){
                 ms.insert(ve[j].second);
             }
             else{
                 ms.erase(ms.find(-ve[j].second));
             }
             j++;

         }while(j<ve.size()&&ve[i].first==ve[j].first);
         if(h!=*ms.rbegin()){
             ans.push_back(make_pair(ve[i].first,h));
             ans.push_back(make_pair(ve[i].first,h=*ms.rbegin()));
         }
         i=j;
     }
     cout<<ans.size()<<endl;
     for(int i=;i<ans.size();i++){
         cout<<ans[i].first<<" "<<ans[i].second<<endl;
     }
 }