Codeforces Beta Round #75 (Div. 2 Only)

Posted 2021-02-12 fighting-sh

Codeforces Beta Round #75 (Div. 2 Only)

http://codeforces.com/contest/92

A

 1 #include<iostream>
 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 100005
 7 typedef long long ll;
 8 typedef unsigned long long ull;
 9 const ull MOD=257;
10 /*#ifndef ONLINE_JUDGE
11         freopen("1.txt","r",stdin);
12 #endif */
13 
14 
15 
16 int main(){
17     #ifndef ONLINE_JUDGE
18      //   freopen("1.txt","r",stdin);
19     #endif
20     std::ios::sync_with_stdio(false);
21     int n,m;
22     cin>>n>>m;
23     int i=0;
24     while(i+1<=m){
25         m-=i+1;
26         i++;
27         if(i==n) i%=n;
28     }
29     cout<<m<<endl;
30 }

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B

模拟+找规律

 1 #include<iostream>
 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 100005
 7 typedef long long ll;
 8 typedef unsigned long long ull;
 9 const ull MOD=257;
10 /*#ifndef ONLINE_JUDGE
11         freopen("1.txt","r",stdin);
12 #endif */
13 
14 ///1
15 
16 int main(){
17     #ifndef ONLINE_JUDGE
18      //   freopen("1.txt","r",stdin);
19     #endif
20     std::ios::sync_with_stdio(false);
21     string str;
22     cin>>str;
23     if(str=="1"){
24         cout<<0;
25         return 0;
26     }
27     int ans=0;
28     for(int i=str.length()-1;i>=0;i--){
29         if(str[i]==‘1‘&&i==0) break;
30         if(str[i]==‘1‘){
31             ans+=2;
32             int l=i;
33             while(l>=0&&str[l]==‘1‘){
34                 str[l]=‘0‘;
35                 l--;
36             }
37             if(l>=0) str[l]=‘1‘;
38         }
39         else{
40             ans++;
41         }
42 
43     }
44     cout<<ans<<endl;
45 }

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C

二分

 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 pb push_back
 7 #define eb emplace_back
 8 #define maxn 1000006
 9 #define eps 1e-8
10 #define pi acos(-1.0)
11 #define rep(k,i,j) for(int k=i;k<j;k++)
12 typedef long long ll;
13 typedef pair<int,int> pii;
14 typedef pair<char,int> pci;
15 typedef pair<pair<int,string>,pii> ppp;
16 typedef unsigned long long ull;
17 /*#ifndef ONLINE_JUDGE
18         freopen("1.txt","r",stdin);
19 #endif */
20 
21 vector<int>ve[35];
22 int book[35];
23 
24 int main(){
25     #ifndef ONLINE_JUDGE
26      //   freopen("1.txt","r",stdin);
27     #endif
28     std::ios::sync_with_stdio(false);
29     string s1,s2;
30     cin>>s1>>s2;
31     int ans=1;
32     for(int i=0;i<s1.length();i++){
33         ve[s1[i]-‘a‘].pb(i);
34     }
35     int pos=-1;
36     int x,tmp;
37     for(int i=0;i<s2.length();i++){
38         x=s2[i]-‘a‘;
39         if(ve[x].size()==0){
40             cout<<-1<<endl;
41             return 0;
42         }
43         tmp=lower_bound(ve[x].begin(),ve[x].end(),pos+1)-ve[x].begin();
44         if(tmp!=ve[x].size()){
45             pos=ve[x][tmp];
46         }
47         else{
48             ans++;
49             pos=lower_bound(ve[x].begin(),ve[x].end(),0)-ve[x].begin();
50             pos=ve[x][pos];
51         }
52      //   cout<<tmp<<" "<<pos<<" "<<ans<<endl;
53       //  cout<<pos<<endl;
54     }
55     cout<<ans<<endl;
56 }

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D

线段树

 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 pb push_back
 7 #define eb emplace_back
 8 #define maxn 100005
 9 #define eps 1e-8
10 #define pi acos(-1.0)
11 #define rep(k,i,j) for(int k=i;k<j;k++)
12 typedef long long ll;
13 typedef pair<int,int> pii;
14 typedef pair<char,int> pci;
15 typedef pair<pair<int,string>,pii> ppp;
16 typedef unsigned long long ull;
17 /*#ifndef ONLINE_JUDGE
18         freopen("1.txt","r",stdin);
19 #endif */
20 
21 int a[maxn];
22 int tree[maxn<<3];
23 int n;
24 
25 void push_up(int rt){
26     tree[rt]=min(tree[rt<<1],tree[rt<<1|1]);
27 }
28 
29 void build(int l,int r,int rt){
30     if(l==r){
31         tree[rt]=a[l];
32         return;
33     }
34     int mid=l+r>>1;
35     build(lson);
36     build(rson);
37     push_up(rt);
38 }
39 
40 int query(int L,int R,int v,int l,int r,int rt){
41     if(l==r&&L<=l&&R>=r){
42         return l;
43     }
44     int mid=l+r>>1;
45     if(L<=mid&&tree[rt<<1]<v){
46         return query(L,R,v,lson);
47     }
48     else if(R>mid&&tree[rt<<1|1]<v){
49         return query(L,R,v,rson);
50     }
51     return -1;
52 }
53 
54 int main(){
55     #ifndef ONLINE_JUDGE
56      //   freopen("1.txt","r",stdin);
57     #endif
58     std::ios::sync_with_stdio(false);
59     cin>>n;
60     for(int i=n;i>=1;i--) cin>>a[i];
61     build(1,n,1);
62     int pos;
63     vector<int>ans;
64     for(int i=1;i<=n;i++){
65         pos=query(1,i,a[i],1,n,1);
66         if(pos==-1) ans.pb(pos);
67         else ans.pb(i-pos-1);
68     }
69     reverse(ans.begin(),ans.end());
70     for(int i=0;i<ans.size();i++) cout<<ans[i]<<" ";
71 }

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E

并查集

 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 pb push_back
 7 #define eb emplace_back
 8 #define maxn 100005
 9 #define eps 1e-8
10 #define pi acos(-1.0)
11 #define rep(k,i,j) for(int k=i;k<j;k++)
12 typedef long long ll;
13 typedef pair<int,int> pii;
14 typedef pair<char,int> pci;
15 typedef pair<pair<int,string>,pii> ppp;
16 typedef unsigned long long ull;
17 const long long MOD=1e9+9;
18 /*#ifndef ONLINE_JUDGE
19         freopen("1.txt","r",stdin);
20 #endif */
21 
22 int n,m;
23 int fa[100005];
24 
25 int Find(int x){
26     int r=x,y;
27     while(x!=fa[x]) x=fa[x];
28     while(r!=x){
29         y=fa[r];
30         fa[r]=x;
31         r=y;
32     }
33     return x;
34 }
35 
36 int main(){
37     #ifndef ONLINE_JUDGE
38      //   freopen("1.txt","r",stdin);
39     #endif
40     std::ios::sync_with_stdio(false);
41     cin>>n>>m;
42     int x,y,xx,yy;
43     ll ans=1;
44     for(int i=0;i<=n;i++) fa[i]=i;
45     for(int i=0;i<m;i++){
46         cin>>x>>y;
47         xx=Find(x),yy=Find(y);
48         if(xx==yy){
49             ans=(ans+ans)%MOD;
50         }
51         else fa[xx]=yy;
52         cout<<ans-1<<endl;
53     }
54 
55 }

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