2021蓝桥模拟赛

1

#include<bits/stdc++.h>
using namespace std;
int cnt;

int is_prime(int n)
{
    if(n==1)return 0;
    for(int i=2;i*i<=n;i++)
        if(n%i==0)return 0;
    return 1;

}


int main()
{
    for(int i=1900;i<=2020;i++)
        if(is_prime(i))cnt++;
    return cout<<cnt<<endl,0;
}

输出： 16

2

#include<bits/stdc++.h>
using namespace std;


int main()
{
    printf("%c",80);
    return 0;
}

输出：P

3

Father = Chilren
F = n-1 （father）
C= n1+2n2 （children）
由 F=C 得 n0=n2+1
由 n0=2021 n2=2020 所以 n>=4041
min_n = 4041

输出：4041

4

#include<bits/stdc++.h>
using namespace std;

int a[150]={0,1,1};
int cnt;

int main()
{
    for(int i=3;i<=100;i++)
        a[i]=(a[i-1]+a[i-2])%3;
    for(int i=3;i<=100;i++)
        if(!a[i])cnt++;
    return cout<<cnt<<endl,0;
}

输出：25

5

#include<bits/stdc++.h>
using namespace std;

int a[30]={0,1,2,4,8,5,10,9,7,3,6,1,2,4,8,5,10,9,7};//power
string s= {0,0,9,9,9,1,2, 2,0,1,2,0,2,1,0,1,0, 1,1};
int ans;

int main()
{

    for(int j=1;j<=10;j++){
        ans=0;
        s[1]=j;
        for(int i=1;i<=18;i++)ans+=a[i]*s[i];
        if(ans%11==1)cout<<j<<endl;
    }
    return 0;
}

输出：8

6

#include<bits/stdc++.h>
using namespace std;

int n;
string s[20]{"-----",".----","..---","...--","....-",".....","-....","--...","---..","----.",};
string in;

int main()
{
    cin>>n;
    while(n--){
        cin>>in;
        for(int i=0;i<in.length();i++)
            cout<<s[in[i]-'0']<<" ";
        cout<<endl;
    }
    return 0;
}

7

#include<bits/stdc++.h>
using namespace std;

string s;
int main()
{
    cin>>s;
    for(int i=0;i<s.length();i++)
        s[i]=(i==0)?toupper(s[i]):tolower(s[i]);
    return cout<<s<<endl,0;
}

8

#include<bits/stdc++.h>
using namespace std;
#define MAXN 1010


int n;
int a[MAXN];
int border(int num){
    if(num-2<1||num+2>n)return 0;
    return 1;
}

int fun(int num)
{
    int max_num=-999999,min_num=0x7fffffff;
    if(border(num)){
        for(int i=num-2;i<=num+2;i++){
            max_num=max(max_num,a[i]);
            min_num=min(min_num,a[i]);
        }
        cout<<max_num-min_num<<" ";
    }
}

int main()
{
    cin>>n;
    for(int i=1;i<=n;i++)cin>>a[i];
    for(int i=1;i<=n;i++)fun(i);
    return cout<<endl,0;
}

9

#include<bits/stdc++.h>
using namespace std;
#define N 100010
int t,n,a[N];

int main()
{
	scanf("%d",&t);
	while(t--){
		scanf("%d",&n);
		for(int i=1;i<=n;i++)scanf("%d",&a[i]);
		deque<int>q;
		int cnt=1;
		for(int i=1;i<=n;i++){
			q.push_back(a[i]);
			while(q.size()!=0&&q.back()==cnt)q.pop_back(),cnt++;
			while(q.size()!=0&&q.front()==cnt)q.pop_front(),cnt++;
		}
		cnt==n+1?printf("YES\n"):printf("No\n");
	}
	return 0;
}