2015-2016 ACM-ICPC, NEERC, Southern Subregional Contest

最新推荐文章于 2025-02-02 22:07:06 发布

原创最新推荐文章于 2025-02-02 22:07:06 发布 · 600 阅读

0 ·

CC 4.0 BY-SA版权

文章标签：

#codeforces #acm-icpc #c++

codeforces 同时被 3 个专栏收录

22 篇文章

订阅专栏

4 篇文章

订阅专栏

二分

4 篇文章

订阅专栏

本文解析了2015-2016年度ACM-ICPC东北欧区域赛南部子区域赛的部分题目，包括A-F及J题的详细解题思路和C++代码实现。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

2015-2016 ACM-ICPC, NEERC, Southern Subregional Contest (Online Mirror, ACM-ICPC Rules, Teams Preferred)

CodeForces 589A

思路：暴力模拟，注意读题，dots和‘+’到‘@’可忽略均有条件。

/*************************************************************************
     File Name: A.cpp
     ID: obsolescence
     BLOG: http://blog.youkuaiyun.com/obsolescence
     LANG: C++ 
     Mail: 384099319@qq.com 
     Created Time: 2016年07月28日 星期四 13时14分02秒
 ************************************************************************/
#include<bits/stdc++.h>
#define Max(x,y) ((x)>(y)?(x):(y))
#define Min(x,y) ((x)<(y)?(x):(y))
#define each(it,v) for(__typeof((v).begin()) it=(v).begin();it!=(v).end();++it)
#define Abs(x,y) ((x)>(y)?((x)-(y)):((y)-(x)))
#define ll long long
#define Mem0(x) memset(x,0,sizeof(x))
#define Mem1(x) memset(x,-1,sizeof(x))
#define MemX(x) memset(x,0x3f,sizeof(x))
#define pb push_back
using namespace std;
const int N=20010;
struct node{
  string s;
  int ord;
  bool operator < (const node &rhs) const {
    return ord < rhs.ord;
  }
}str[N];
map<string,int> my_map;
int cnt[N];

int main() {
  int n,i,j;
  ios::sync_with_stdio(0);
  while (cin>>n) {
    int top=0;
    Mem0(cnt);
    for (i=0; i<n; ++i) {
      cin>>str[i].s;
      for (j=0; str[i].s[j]; ++j)
        if (str[i].s[j]=='@') break;
      string tmp="",tmp1="bmail.com",tmp2="";
      for (++j; str[i].s[j]; ++j) {
        if (str[i].s[j]>='A' && str[i].s[j]<='Z') tmp+=str[i].s[j]-'A'+'a';
        else tmp+=str[i].s[j];
      }
      //cout<<"tmp="<<tmp<<endl;
      bool flag=0;
      if (tmp==tmp1) flag=1;
      for (j=0; str[i].s[j]; ++j) {
        if (str[i].s[j]=='@') {
          tmp2+=str[i].s[j];
          break;
        }
        if (str[i].s[j]=='.' && flag) continue;
        if (str[i].s[j]=='+' && flag) {
          while (str[i].s[j+1]!='@') ++j;
        } else if (str[i].s[j]>='A' && str[i].s[j]<='Z') {
          tmp2+=str[i].s[j]-'A'+'a';
        } else tmp2+=str[i].s[j];
      }
      tmp2+=tmp;
      if (!my_map[tmp2]) {
        my_map[tmp2]=++top;
      }
      //cout<<"tmp2="<<tmp2<<endl;
      cnt[my_map[tmp2]]++;
      str[i].ord=my_map[tmp2];
    }
    cout<<top<<'\n';
    sort(str,str+n);
    for (i=0; i<n;) {
      int tmp=cnt[str[i].ord];
      cout<<tmp;
      while (tmp--) {
        cout<<' '<<str[i].s;
        ++i;
      }
      cout<<'\n';
    }
  }
}

CodeForces 589B

思路：令x有序后，暴力枚举y

/*************************************************************************
     File Name: B.cpp
     ID: obsolescence
     BLOG: http://blog.youkuaiyun.com/obsolescence
     LANG: C++ 
     Mail: 384099319@qq.com 
     Created Time: 2016年07月28日 星期四 14时01分33秒
 ************************************************************************/
#include<bits/stdc++.h>
#define Max(x,y) ((x)>(y)?(x):(y))
#define Min(x,y) ((x)<(y)?(x):(y))
#define each(it,v) for(__typeof((v).begin()) it=(v).begin();it!=(v).end();++it)
#define Abs(x,y) ((x)>(y)?((x)-(y)):((y)-(x)))
#define ll long long
#define Mem0(x) memset(x,0,sizeof(x))
#define Mem1(x) memset(x,-1,sizeof(x))
#define MemX(x) memset(x,0x3f,sizeof(x))
#define pb push_back
using namespace std;
const int N=4010;
struct node{
  ll a,b;
  bool operator < (const node &rhs) const {
    return a < rhs.a;
  }
}cake[N];
ll b[N];

int main() {
  int n,i,j,k;
  while (cin>>n) {
    for (i=0; i<n; ++i) {
      cin>>cake[i].a>>cake[i].b;
      if (cake[i].a<cake[i].b)
        swap(cake[i].a,cake[i].b);
    }
    sort(cake,cake+n);
    ll ans=0,tmp,ansA,ansB;
    for (i=0; i<n; ++i) {
      for (j=i,k=0; j<n; ++j)
        b[k++]=cake[j].b;
      sort(b,b+k);
      for (j=0; j<k; ++j) {
        tmp=cake[i].a*b[j]*(k-j);
        if (ans<tmp) {
          ans=tmp;
          ansA=cake[i].a;
          ansB=b[j];
        }
      }
    }
    cout<<ans<<'\n'<<ansA<<' '<<ansB<<'\n';
  }
}

CodeForces 589C

CodeForces 589D

CodeForces 589E

CodeForces 589F

思路：二分+贪心。二分时间，贪心的去安排最大不相交区间（即令b升序排序，具体证明参考此处）

/*************************************************************************
     File Name: F.cpp
     ID: obsolescence
     BLOG: http://blog.youkuaiyun.com/obsolescence
     LANG: C++ 
     Mail: 384099319@qq.com 
     Created Time: 2016年07月28日 星期四 22时05分04秒
 ************************************************************************/
#include<bits/stdc++.h>
#define Max(x,y) ((x)>(y)?(x):(y))
#define Min(x,y) ((x)<(y)?(x):(y))
#define each(it,v) for(__typeof((v).begin()) it=(v).begin();it!=(v).end();++it)
#define Abs(x,y) ((x)>(y)?((x)-(y)):((y)-(x)))
#define ll long long
#define Mem0(x) memset(x,0,sizeof(x))
#define Mem1(x) memset(x,-1,sizeof(x))
#define MemX(x) memset(x,0x3f,sizeof(x))
#define pb push_back
using namespace std;
const int N=110,M=1e5+10,INF=0x3f3f3f3f;
struct node{
  int a,b;
  bool operator < (const node &rhs) const {
    return b<rhs.b;
  }
}t[N];
bool f[M];

int main() {
  int n,i,j;
  while (~scanf("%d",&n)) {
    int maxn=0,minn=INF,min_dis=INF;
    for (i=0; i<n; ++i) {
      scanf("%d%d",&t[i].a,&t[i].b);
      minn=Min(minn,t[i].a);
      maxn=Max(maxn,t[i].b);
      min_dis=Min(min_dis,t[i].b-t[i].a);
    }
    sort(t,t+n);
    int low=0,high=Min(min_dis,(maxn-minn)/n),mid,ans=0;
    while (low<=high) {
      Mem0(f);
      mid=(low+high)>>1;
      //cout<<"low="<<low<<" high="<<high<<" mid="<<mid<<endl;
      int cnt,flag=0;
      for (i=0; i<n; ++i) {
        cnt=0;
        for (j=t[i].a; j<t[i].a+mid+cnt; ++j)
          if (f[j]) cnt++;
          else f[j]=1;
        if (j>t[i].b) flag=1;
      }
      if (!flag) low=mid+1,ans=mid;
      else high=mid-1;
    }
    printf("%d\n",ans*n);
  }
}

CodeForces 589G

CodeForces 589H

CodeForces 589I 水题，签到题

CodeForces 589J

思路：bfs

/*************************************************************************
     File Name: J.cpp
     ID: obsolescence
     BLOG: http://blog.youkuaiyun.com/obsolescence
     LANG: C++ 
     Mail: 384099319@qq.com 
     Created Time: 2016年07月28日 星期四 15时39分32秒
 ************************************************************************/
#include<bits/stdc++.h>
#define Max(x,y) ((x)>(y)?(x):(y))
#define Min(x,y) ((x)<(y)?(x):(y))
#define each(it,v) for(__typeof((v).begin()) it=(v).begin();it!=(v).end();++it)
#define Abs(x,y) ((x)>(y)?((x)-(y)):((y)-(x)))
#define ll long long
#define Mem0(x) memset(x,0,sizeof(x))
#define Mem1(x) memset(x,-1,sizeof(x))
#define MemX(x) memset(x,0x3f,sizeof(x))
#define pb push_back
using namespace std;
const int N=15;
char mp[N][N],dir[]={'U','R','D','L'};
bool vis[N][N][5],check[N][N];
int mx[]={-1,0,1,0},my[]={0,1,0,-1};
struct node{
  int x,y,step,d;
}s,t;

int main() {
  int h,w,i,j,k;
  while (~scanf("%d%d",&h,&w)) {
    Mem0(vis),Mem0(check);
    for (i=0; i<h; ++i) {
      scanf("%s",mp[i]);
      for (j=0; j<w; ++j)
        if (mp[i][j]!='.' && mp[i][j]!='*') {
          s.x=i,s.y=j,s.step=1;
          for (k=0; k<4; ++k)
            if (mp[i][j]==dir[k]) s.d=k;
        }
    }
    queue<node> q;
    q.push(s);
    check[s.x][s.y]=1;
    int ans=1;
    while (!q.empty()) {
      s=q.front();
      q.pop();
      ans=Max(ans,s.step);
      t=s,t.x+=mx[t.d],t.y+=my[t.d];
      int cnt=0;
      while (t.x<0 || t.x>=h || t.y<0 || t.y>=w) {
        cnt++;
        s.d=(s.d+1)%4;
        t=s,t.x+=mx[t.d],t.y+=my[t.d];
        if(cnt>=4)break;
      }
      if (t.x>=0 && t.x<h && t.y>=0 && t.y<w) {
        if (vis[t.x][t.y][t.d]) break;
        vis[t.x][t.y][t.d]=1;
        if (mp[t.x][t.y]!='*') {
          if (!check[t.x][t.y]) {
            t.step++;
            check[t.x][t.y]=1;
          }
          q.push(t);
        } else {
          s.d=(s.d+1)%4;
          q.push(s);
        }
      }
    }
    printf("%d\n",ans);
  }
}