Codeforces Beta Round #5

Posted 2021-02-07 fighting-sh

Codeforces Beta Round #5

http://codeforces.com/contest/5

A

模拟题

 1 #include<bits/stdc++.h>
 2 using namespace std;
 3 #define lson l,mid,rt<<1
 4 #define rson mid+1,r,rt<<1|1
 5 #define sqr(x) ((x)*(x))
 6 typedef long long ll;
 7 /*#ifndef ONLINE_JUDGE
 8         freopen("1.txt","r",stdin);
 9 #endif */
10 
11 
12 int main(){
13     std::ios::sync_with_stdio(false);
14     #ifndef ONLINE_JUDGE
15         freopen("1.txt","r",stdin);
16     #endif
17     set<string>se;
18     string str;
19     int i;
20     int ans=0;
21     while(getline(cin,str)){
22         if(str.length()==0) break;
23         if(str[0]==‘+‘||str[0]==‘-‘){
24             if(str[0]==‘+‘){
25                 str=str.substr(1);
26                 se.insert(str);
27             }
28             else{
29                 str=str.substr(1);
30                 se.erase(str);
31             }
32         }
33         else{
34             for(i=0;i<str.length();i++){
35                 if(str[i]==‘:‘) break;
36             }
37            // cout<<i<<endl;
38             ans+=se.size()*(str.length()-1-i);
39         }
40     }
41     cout<<ans<<endl;
42     return 0;
43 }

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B

画图题

 1 #include<bits/stdc++.h>
 2 using namespace std;
 3 #define lson l,mid,rt<<1
 4 #define rson mid+1,r,rt<<1|1
 5 #define sqr(x) ((x)*(x))
 6 typedef long long ll;
 7 /*#ifndef ONLINE_JUDGE
 8         freopen("1.txt","r",stdin);
 9 #endif */
10 string str[1005];
11 
12 int main(){
13     std::ios::sync_with_stdio(false);
14     #ifndef ONLINE_JUDGE
15         freopen("1.txt","r",stdin);
16     #endif
17     int n=0;
18     while(getline(cin,str[n++]));
19     int Max=0;
20     n--;
21     for(int i=0;i<n;i++){
22         int len=str[i].length();
23         Max=max(Max,len);
24     }
25     for(int i=0;i<Max+2;i++){
26         cout<<‘*‘;
27     }
28     cout<<endl;
29     int cc=1;
30     for(int i=0;i<n;i++){
31         cout<<‘*‘;
32         int k=Max-str[i].length();
33         int tou=k/2;
34         int wei=k/2;
35         k=k-wei-tou;
36         if(k){
37             if(cc%2) wei++,cc++;
38             else tou++,cc++;
39         }
40         for(int j=0;j<tou;j++) cout<<‘ ‘;
41         cout<<str[i];
42         for(int j=0;j<wei;j++) cout<<‘ ‘;
43         cout<<‘*‘<<endl;
44     }
45     for(int i=0;i<Max+2;i++){
46         cout<<‘*‘;
47     }
48     cout<<endl;
49     return 0;
50 }

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C

找到匹配最大字符串，直接暴力模拟

 1 #include<bits/stdc++.h>
 2 using namespace std;
 3 #define lson l,mid,rt<<1
 4 #define rson mid+1,r,rt<<1|1
 5 #define sqr(x) ((x)*(x))
 6 typedef long long ll;
 7 /*#ifndef ONLINE_JUDGE
 8         freopen("1.txt","r",stdin);
 9 #endif */
10 
11 int a[1000005];
12 int len[1000005];
13 
14 int main(){
15     std::ios::sync_with_stdio(false);
16     #ifndef ONLINE_JUDGE
17         freopen("1.txt","r",stdin);
18     #endif
19     string str;
20     cin>>str;
21     stack<int>st;
22     /// () (()) ()
23     memset(a,-1,sizeof(a));
24     for(int i=0;i<str.length();i++){
25         if(str[i]==‘(‘){
26             st.push(i);
27         }
28         else{
29             if(st.empty()){
30                 continue;
31             }
32             else{
33                 a[i]=st.top();
34                 st.pop();
35             }
36         }
37     }
38     int Max=0,num=0;
39     for(int i=0;i<str.length();i++){
40         if(a[i]!=-1){
41             len[i]=(a[i]>0?len[a[i]-1]:0)+i-a[i]+1;
42             if(Max<len[i]){
43                 Max=len[i];
44                 num=1;
45             }
46             else if(Max==len[i]) num++;
47         }
48     }
49 
50 
51     if(!Max) cout<<"0 1"<<endl;
52     else{
53         cout<<Max<<" "<<num<<endl;
54     }
55     return 0;
56 }

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D

物理题

 1 #include<bits/stdc++.h>
 2 using namespace std;
 3 #define lson l,mid,rt<<1
 4 #define rson mid+1,r,rt<<1|1
 5 #define sqr(x) ((x)*(x))
 6 typedef long long ll;
 7 /*#ifndef ONLINE_JUDGE
 8         freopen("1.txt","r",stdin);
 9 #endif */
10 double a,v,l,d,w,ans,t1,t2,t3,x1,x2,x3;
11 int flag;
12 
13 int main(){
14     scanf("%lf%lf",&a,&v);
15     scanf("%lf%lf%lf",&l,&d,&w);
16     t1=v/a;
17     x1=a*t1*t1/2;
18     if(w<v)
19         flag=1;
20     if(flag==1){
21         t2=w/a;
22         x2=a*t2*t2/2;
23         if(x2<d){
24             t3=(v-w)/a;
25             x3=w*t3+a*t3*t3/2;
26             if(x1+x3<d)
27                 ans=t1+t3+(d-x1-x3)/v;
28             else
29                 ans=t2+2*(sqrt(a*(d-x2)+w*w)-w)/a;
30             if(x3<l-d)
31                 ans+=t3+(l-d-x3)/v;
32             else
33                 ans+=(sqrt(2*a*(l-d)+w*w)-w)/a;
34         }
35         else
36             flag=0;
37     }
38     if(flag==0){
39         if(x1<l)
40             ans=t1+(l-x1)/v;
41         else
42             ans=sqrt(2*l/a);
43     }
44     printf("%.6f
",ans);
45     return 0;
46 }

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E

首先我们把环变成一个链，然后用一个并查集的思想，处理每一座山左边第一个比这个山高的山是哪个，右边第一个比这个山高的是哪个，这个区域内和这个山高度一样的山有多少

然后跑一发并查集就好了

 1 #include<bits/stdc++.h>
 2 using namespace std;
 3 #define lson l,mid,rt<<1
 4 #define rson mid+1,r,rt<<1|1
 5 #define sqr(x) ((x)*(x))
 6 #define maxn 1000010
 7 typedef long long ll;
 8 /*#ifndef ONLINE_JUDGE
 9         freopen("1.txt","r",stdin);
10 #endif */
11 
12 int a[maxn];
13 int b[maxn];
14 int l[maxn];
15 int r[maxn];
16 int k[maxn];
17 int main()
18 {
19     int n;
20     cin>>n;
21     int p=-1;
22     for(int i=0;i<n;i++)
23     {
24         cin>>a[i];
25         if(p==-1)
26             p=i;
27         else if(a[i]>a[p])
28         {
29             p=i;
30         }
31     }
32     for(int i=0;i<n;i++)
33         b[i]=a[(i+p+n)%n];
34     b[n]=a[p];
35     for(int i=1;i<n;i++)
36     {
37         l[i]=i-1;
38         while(l[i]>0&&b[i]>=b[l[i]])
39             l[i]=l[l[i]];
40     }
41     k[n]=0;
42     for(int i=n-1;i>=0;i--)
43     {
44         r[i]=i+1;
45         while(r[i]<n&&b[i]>b[r[i]])
46             r[i]=r[r[i]];
47         if(r[i]<n&&b[i]==b[r[i]])
48         {
49             k[i]=k[r[i]]+1;
50             r[i]=r[r[i]];
51         }
52     }
53     ll ans=0;
54     for(int i=1;i<n;i++)
55     {
56         ans+=k[i];
57         ans+=1;
58         if(l[i]!=0||r[i]!=n)
59             ans++;
60     }
61     cout<<ans<<endl;
62 }

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