Codeforces Beta Round #75 (Div. 2 Only)

Codeforces Beta Round #75 (Div. 2 Only)

http://codeforces.com/contest/92

A

#include<iostream>
using namespace std;
#define lson l,mid,rt<<1
#define rson mid+1,r,rt<<1|1
#define sqr(x) ((x)*(x))
#define maxn 100005
typedef long long ll;
typedef unsigned long long ull;
const ull MOD=257;
/*#ifndef ONLINE_JUDGE
        freopen("1.txt","r",stdin);
#endif */



int main(){
    #ifndef ONLINE_JUDGE
     //   freopen("1.txt","r",stdin);
    #endif
    std::ios::sync_with_stdio(false);
    int n,m;
    cin>>n>>m;
    int i=0;
    while(i+1<=m){
        m-=i+1;
        i++;
        if(i==n) i%=n;
    }
    cout<<m<<endl;
}

B

模拟+找规律

#include<iostream>
using namespace std;
#define lson l,mid,rt<<1
#define rson mid+1,r,rt<<1|1
#define sqr(x) ((x)*(x))
#define maxn 100005
typedef long long ll;
typedef unsigned long long ull;
const ull MOD=257;
/*#ifndef ONLINE_JUDGE
        freopen("1.txt","r",stdin);
#endif */

///1

int main(){
    #ifndef ONLINE_JUDGE
     //   freopen("1.txt","r",stdin);
    #endif
    std::ios::sync_with_stdio(false);
    string str;
    cin>>str;
    if(str=="1"){
        cout<<0;
        return 0;
    }
    int ans=0;
    for(int i=str.length()-1;i>=0;i--){
        if(str[i]=='1'&&i==0) break;
        if(str[i]=='1'){
            ans+=2;
            int l=i;
            while(l>=0&&str[l]=='1'){
                str[l]='0';
                l--;
            }
            if(l>=0) str[l]='1';
        }
        else{
            ans++;
        }

    }
    cout<<ans<<endl;
}

C

二分

#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 eb emplace_back
#define maxn 1000006
#define eps 1e-8
#define pi acos(-1.0)
#define rep(k,i,j) for(int k=i;k<j;k++)
typedef long long ll;
typedef pair<int,int> pii;
typedef pair<char,int> pci;
typedef pair<pair<int,string>,pii> ppp;
typedef unsigned long long ull;
/*#ifndef ONLINE_JUDGE
        freopen("1.txt","r",stdin);
#endif */

vector<int>ve[35];
int book[35];

int main(){
    #ifndef ONLINE_JUDGE
     //   freopen("1.txt","r",stdin);
    #endif
    std::ios::sync_with_stdio(false);
    string s1,s2;
    cin>>s1>>s2;
    int ans=1;
    for(int i=0;i<s1.length();i++){
        ve[s1[i]-'a'].pb(i);
    }
    int pos=-1;
    int x,tmp;
    for(int i=0;i<s2.length();i++){
        x=s2[i]-'a';
        if(ve[x].size()==0){
            cout<<-1<<endl;
            return 0;
        }
        tmp=lower_bound(ve[x].begin(),ve[x].end(),pos+1)-ve[x].begin();
        if(tmp!=ve[x].size()){
            pos=ve[x][tmp];
        }
        else{
            ans++;
            pos=lower_bound(ve[x].begin(),ve[x].end(),0)-ve[x].begin();
            pos=ve[x][pos];
        }
     //   cout<<tmp<<" "<<pos<<" "<<ans<<endl;
      //  cout<<pos<<endl;
    }
    cout<<ans<<endl;
}

D

线段树

#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 eb emplace_back
#define maxn 100005
#define eps 1e-8
#define pi acos(-1.0)
#define rep(k,i,j) for(int k=i;k<j;k++)
typedef long long ll;
typedef pair<int,int> pii;
typedef pair<char,int> pci;
typedef pair<pair<int,string>,pii> ppp;
typedef unsigned long long ull;
/*#ifndef ONLINE_JUDGE
        freopen("1.txt","r",stdin);
#endif */

int a[maxn];
int tree[maxn<<3];
int n;

void push_up(int rt){
    tree[rt]=min(tree[rt<<1],tree[rt<<1|1]);
}

void build(int l,int r,int rt){
    if(l==r){
        tree[rt]=a[l];
        return;
    }
    int mid=l+r>>1;
    build(lson);
    build(rson);
    push_up(rt);
}

int query(int L,int R,int v,int l,int r,int rt){
    if(l==r&&L<=l&&R>=r){
        return l;
    }
    int mid=l+r>>1;
    if(L<=mid&&tree[rt<<1]<v){
        return query(L,R,v,lson);
    }
    else if(R>mid&&tree[rt<<1|1]<v){
        return query(L,R,v,rson);
    }
    return -1;
}

int main(){
    #ifndef ONLINE_JUDGE
     //   freopen("1.txt","r",stdin);
    #endif
    std::ios::sync_with_stdio(false);
    cin>>n;
    for(int i=n;i>=1;i--) cin>>a[i];
    build(1,n,1);
    int pos;
    vector<int>ans;
    for(int i=1;i<=n;i++){
        pos=query(1,i,a[i],1,n,1);
        if(pos==-1) ans.pb(pos);
        else ans.pb(i-pos-1);
    }
    reverse(ans.begin(),ans.end());
    for(int i=0;i<ans.size();i++) cout<<ans[i]<<" ";
}

E

并查集

#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 eb emplace_back
#define maxn 100005
#define eps 1e-8
#define pi acos(-1.0)
#define rep(k,i,j) for(int k=i;k<j;k++)
typedef long long ll;
typedef pair<int,int> pii;
typedef pair<char,int> pci;
typedef pair<pair<int,string>,pii> ppp;
typedef unsigned long long ull;
const long long MOD=1e9+9;
/*#ifndef ONLINE_JUDGE
        freopen("1.txt","r",stdin);
#endif */

int n,m;
int fa[100005];

int Find(int x){
    int r=x,y;
    while(x!=fa[x]) x=fa[x];
    while(r!=x){
        y=fa[r];
        fa[r]=x;
        r=y;
    }
    return x;
}

int main(){
    #ifndef ONLINE_JUDGE
     //   freopen("1.txt","r",stdin);
    #endif
    std::ios::sync_with_stdio(false);
    cin>>n>>m;
    int x,y,xx,yy;
    ll ans=1;
    for(int i=0;i<=n;i++) fa[i]=i;
    for(int i=0;i<m;i++){
        cin>>x>>y;
        xx=Find(x),yy=Find(y);
        if(xx==yy){
            ans=(ans+ans)%MOD;
        }
        else fa[xx]=yy;
        cout<<ans-1<<endl;
    }

}