Codeforces Round #450 (Div. 2) 题解

A

#include<bits/stdc++.h> 
using namespace std;
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
                        For(j,m-1) cout<<a[i][j]<<' ';\
                        cout<<a[i][m]<<endl; \
                        } 
#pragma
#define
#define
#define
typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
ll mul(ll a,ll b){return (a*b)%F;}
ll add(ll a,ll b){return (a+b)%F;}
ll sub(ll a,ll b){return ((a-b)%F+F)%F;}
void upd(ll &a,ll b){a=(a%F+b%F)%F;}
inline int read()
{
    int x=0,f=1; char ch=getchar();
    while(!isdigit(ch)) {if (ch=='-') f=-1; ch=getchar();}
    while(isdigit(ch)) { x=x*10+ch-'0'; ch=getchar();}
    return x*f;
} 
int main()
{
//  freopen("A.in","r",stdin);
//  freopen(".out","w",stdout);

    int n=read(),px=0,py=0;
    For(i,n) {
        int x=read(),y=read();
        px+=(x>0);
    } 
    if(px==1||px==n-1) puts("Yes");
    else if(px==0||px==n)puts("Yes");
    else puts("No");

    return 0;
}

B

#include<bits/stdc++.h> 
using namespace std;
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
                        For(j,m-1) cout<<a[i][j]<<' ';\
                        cout<<a[i][m]<<endl; \
                        } 
#pragma
#define
#define
#define
typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
ll mul(ll a,ll b){return (a*b)%F;}
ll add(ll a,ll b){return (a+b)%F;}
ll sub(ll a,ll b){return ((a-b)%F+F)%F;}
void upd(ll &a,ll b){a=(a%F+b%F)%F;}
inline int read()
{
    int x=0,f=1; char ch=getchar();
    while(!isdigit(ch)) {if (ch=='-') f=-1; ch=getchar();}
    while(isdigit(ch)) { x=x*10+ch-'0'; ch=getchar();}
    return x*f;
} 
int main()
{
//  freopen("B.in","r",stdin);
//  freopen(".out","w",stdout);
    ll a=read(),b=read(),c=read();
    ll ans=a%b;
    For(i,9000000) {
        ans*=10;
        ll p=ans/b;
        ans%=b;
        if(p==c) cout<<i<<endl,exit(0);
    }
    puts("-1");

    return 0;
}

C

#include<bits/stdc++.h> 
using namespace std;
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
                        For(j,m-1) cout<<a[i][j]<<' ';\
                        cout<<a[i][m]<<endl; \
                        } 
#pragma
#define
#define
#define
typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
ll mul(ll a,ll b){return (a*b)%F;}
ll add(ll a,ll b){return (a+b)%F;}
ll sub(ll a,ll b){return ((a-b)%F+F)%F;}
void upd(ll &a,ll b){a=(a%F+b%F)%F;}
inline int read()
{
    int x=0,f=1; char ch=getchar();
    while(!isdigit(ch)) {if (ch=='-') f=-1; ch=getchar();}
    while(isdigit(ch)) { x=x*10+ch-'0'; ch=getchar();}
    return x*f;
} 
#define
int n,a[MAXN];
int pre[MAXN];
int c[MAXN];
bool b[MAXN];
int main()
{
//  freopen("C.in","r",stdin);
//  freopen(".out","w",stdout);
    n=read();
    For(i,n) a[i]=read();
    if(n==1) {
        puts("1") ;return 0;
    }
    if(n==2) {
        puts("1");return 0;
    }
    int mx1=0,mx2=0;
    For(i,n) {
        if(mx2>a[i]) {
        }else if (mx1>a[i]) {
            c[mx1]++;   
        }
        int p=a[i];
        b[i]=(mx1<p);
        if(p>mx1) mx2=mx1,mx1=p;
        else if(p>mx2) mx2=p;
    }
    int ans=-INF,px=-1;
    For(i,n) {
        int p=c[a[i]]-(b[i]==1);
        if(p>ans) ans=p,px=a[i];
        else if(p==ans) px=min(px,a[i]);
    }
    cout<<px<<endl;

    return 0;
}

D

#include<bits/stdc++.h> 
using namespace std;
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
#define
                        For(j,m-1) cout<<a[i][j]<<' ';\
                        cout<<a[i][m]<<endl; \
                        } 
#pragma
#define
#define
#define
typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
inline int read()
{
    int x=0,f=1; char ch=getchar();
    while(!isdigit(ch)) {if (ch=='-') f=-1; ch=getchar();}
    while(isdigit(ch)) { x=x*10+ch-'0'; ch=getchar();}
    return x*f;
} 
#define
ll pow2(ll a,ll b){
    if(b==0) return 1;
    if (b==1)return a%F;
    ll p=pow2(a,b/2);
    p=p*p%F;
    if(b&1) p=p*a%F;
    return p;
}
ll f[MAXN];
int main()
{
//  freopen("D.in","r",stdin);
//  freopen(".out","w",stdout);

    ll x=read(),y=read();
    if(y%x) puts("0"),exit(0);
    y/=x;
    ll n=y;
    vi v;
    for(ll i=1;i*i<=n;i++) if(n%i==0){
        v.pb(i);
        if(i*i!=n) v.pb(n/i);
    }
    sort(ALL(v));
    int sz=v.size();
    for(int i=sz-1;i>=0;i--) {
        f[i]=pow2(2,n/v[i]-1);
        for(int j=i+1;j<sz;j++) if(v[j]%v[i]==0) {
            f[i]=(F+f[i]-f[j])%F;
        }
    }   
    cout<<f[0]<<endl;
    return 0;
}