天梯赛初赛 进阶题 题解

L2-009 抢红包

题目链接：

https://www.patest.cn/contests/gplt/L2-009

简单题，结构体排序

#include <iostream>#include <string.h>#include <string>#include <stdio.h>#include <math.h>#include <algorithm>#include <stdlib.h>#include <map>#include <stack>#include <queue>using namespace std;typedef long long int LL;const int maxn=1e9;int n,m;struct Node{  int pos;  int mon;  int num;}res[10004];int cmp(Node a,Node b){  if(a.mon==b.mon&&a.num==b.num)    return a.pos<b.pos;  else if(a.mon==b.mon)    return a.num>b.num;  return a.mon>b.mon;}int main(){  int x,y;  scanf("%d",&n);  for(int i=1;i<=n;i++)  {    res[i].pos=i;    res[i].mon=0;    res[i].num=0;  }  for(int i=1;i<=n;i++)  {    scanf("%d",&m);    int num=0;    for(int j=1;j<=m;j++)    {      scanf("%d%d",&x,&y);      res[x].mon+=y;      res[x].num++;      num+=y;    }    res[i].mon-=num;  }  sort(res+1,res+n+1,cmp);  for(int i=1;i<=n;i++)  {    printf("%d %.2f\n",res[i].pos,1.0*res[i].mon/100);  }  return 0;}

L2-010 排座位

题目链接：

https://www.patest.cn/contests/gplt/L2-010

并查集，把是朋友的并在一起，敌对的连一条边

#include <iostream>#include <string.h>#include <algorithm>#include <stdlib.h>#include <stdio.h>#include <math.h>using namespace std;int father[105];int d[105][105];int n,m,k;int find(int x){    if(x!=father[x])        father[x]=find(father[x]);    return father[x];}int main(){    int x,y,z;    scanf("%d%d%d",&n,&m,&k);    for(int i=1;i<=n;i++)        father[i]=i;    for(int i=1;i<=m;i++)    {        scanf("%d%d%d",&x,&y,&z);        if(z==-1)        {            d[x][y]=-1;            d[y][x]=-1;            continue;        }        int fx=find(x);        int fy=find(y);        if(fx!=fy)            father[fx]=fy;    }    for(int i=1;i<=k;i++)    {        scanf("%d%d",&x,&y);        find(x),find(y);        if(father[x]==father[y]&&d[x][y]!=-1)            printf("No problem\n");        else if(father[x]==father[y]&&d[x][y]==-1)            printf("OK but...\n");        else if(father[x]!=father[y]&&d[x][y]==-1)            printf("No way\n");        else if(father[x]!=father[y]&&d[x][y]!=-1)            printf("OK\n");    }    return 0;}

L2-011 玩转二叉树

题目链接：

https://www.patest.cn/contests/gplt/L2-011

还原二叉树，反转就是在广搜的时候先右子树，再左子树。

#include <iostream>#include <string.h>#include <string>#include <stdio.h>#include <math.h>#include <algorithm>#include <stdlib.h>#include <map>#include <stack>#include <queue>using namespace std;typedef long long int LL;const int maxn=1e9;typedef struct Tree{    int data;    Tree *lchild;    Tree *rchild;}a[40];int post[40];int in[40];int n;int ans[40];void dfs(int l1,int r1,int l2,int r2,Tree* &root){  root=new Tree();    int i;    for( i=l1;i<=r1;i++)        if(in[i]==post[l2])            break;    root->data=post[l2];    if(i==l1)        root->lchild=NULL;    else        dfs(l1,i-1,l2+1,l2+i-l1,root->lchild);    if(i==r1)        root->rchild=NULL;    else        dfs(i+1,r1,r2-(r1-i)+1,r2,root->rchild);  }int cnt;void bfs(Tree *tree){  queue<Tree*> q;  q.push(tree);  while(!q.empty())  {    Tree *root=q.front();    q.pop();    ans[cnt++]=root->data;    if(root->rchild!=NULL)      q.push(root->rchild);    if(root->lchild!=NULL)      q.push(root->lchild);  }}int main(){    scanf("%d",&n);    for(int i=1;i<=n;i++)            scanf("%d",&in[i]);    for(int i=1;i<=n;i++)            scanf("%d",&post[i]);                Tree *tree;    cnt=0;        dfs(1,n,1,n,tree);    bfs(tree);    for(int i=0;i<n;i++)    {      if(i==n-1)        printf("%d\n",ans[i]);      else        printf("%d ",ans[i]);    }    return 0;}

L2-012 关于堆的判读

题目链接：

https://www.patest.cn/contests/gplt/L2-012

最小堆是一颗完全二叉树，所以我们可以用数组模拟，然后插入的时候比较自己和父节点的大小即可，

#include <iostream>#include <string.h>#include <math.h>#include <stdio.h>#include <stdlib.h>#include <algorithm>#include <string>#include <map>using namespace std;int n,m;int a[1005];string b,c;map<int,int>mm;int cnt;void insert(int x){    a[++cnt]=x;    int j=cnt;    while(j>1)    {        if(a[j/2]>a[j])        {      mm[a[j/2]]=j;            swap(a[j/2],a[j]);        j=j/2;        }        else            break;    }  mm[x]=j;}int main(){    int x,y;    scanf("%d%d",&n,&m);    cnt=0;    for(int i=1;i<=n;i++)    {        scanf("%d",&x);        insert(x);    }  for(int i=1;i<=m;i++)  {    cin>>x>>b;    if(b=="is")    {      cin>>b;      if(b=="the")      {        cin>>b;        if(b=="root")        {          if(a[1]==x) cout<<"T"<<endl;          else cout<<"F"<<endl;          continue;        }        else        {                    cin>>b>>y;          if(mm[y]/2==mm[x]) cout<<"T"<<endl;          else cout<<"F"<<endl;          continue;        }      }      else      {        cin>>b>>c>>y;        if(mm[x]/2==mm[y]) cout<<"T"<<endl;        else cout<<"F"<<endl;        continue;      }    }    else    {      cin>>y>>b>>c;            if(min(mm[x],mm[y])%2==0&&abs(mm[y]-mm[x])==1) cout<<"T"<<endl;      else cout<<"F"<<endl;      continue;    }  }  return 0;}