蓝桥杯第十一届C/C++ A组

女爷i 2022-11-17 13:34 161阅读 0赞

### A ###

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80Mzk1OTc0Mw_size_16_color_FFFFFF_t_70]

#include<bits/stdc++.h>
    using namespace std;
    int main(){
        
         int i,x,out=0;
         for(i=1;i<=2020;++i){
        
                int s=i;
            while(s){
        
              x=s%10;
              s/=10;
              if(x==2)
                    out++;
            }
    
         }
         cout<<out<<endl;//624
    return 0;}

### B ###

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80Mzk1OTc0Mw_size_16_color_FFFFFF_t_70 1]  
【】不需要j!=i;第一次是这样第二个for循环条件j<=2020&&j!=i.发现这样是不对的。

#include<bits/stdc++.h>
    using namespace std;
    int gcd(int i,int j){
        
         return (!j)?i:gcd(j,i%j);
    }
    int main(){
        
        int i,j,out=0;
        for(i=1;i<=2020;++i){
        
            for(j=1;j<=2020;++j){
        //不对，不用j!=i
                if(gcd(i,j)==1){
        
                    out++;
                }
            }
        }
    
        cout<<out<<endl;//2481215
    return 0;}

### C ###

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80Mzk1OTc0Mw_size_16_color_FFFFFF_t_70 2]  
草稿纸上找规律，发现等于20平方+19平方，761  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80Mzk1OTc0Mw_size_16_color_FFFFFF_t_70 3]

### D ###

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80Mzk1OTc0Mw_size_16_color_FFFFFF_t_70 4]

#include<bits/stdc++.h>
    using namespace std;
    int a[7][7]={
        0};
    int sel[7];
    int vis[7];
    void dfs(int pos){
        
         for(int i=0;i<7;++i){
        
            if(a[pos][i]&&sel[i]&&vis[i]==0){
        
                vis[i]=1;
                dfs(i);
            }
         }
    }
    int check(){
        
        int sum=0;
        memset(vis,0,sizeof(vis));
        for(int i=0;i<7;++i)
        {
        
            if(sel[i]&&vis[i]==0){
        
               sum++;
               vis[i]=1;
               dfs(i);
            }
        }
        if(sum==1) return 1;
        else return 0;
    }
    void change2(int b){
        
         memset(sel,0,sizeof(sel));
         int l=0;
         while(b){
        
            sel[l++]=b%2;//二进制
            b/=2;
         }
    
    }
    int main(){
        
         a[0][1]=a[1][0]=1;
         a[0][5]=a[5][0]=1;
         a[1][2]=a[2][1]=1;
         a[2][3]=a[3][2]=1;
         a[3][4]=a[4][3]=1;
         a[4][5]=a[5][4]=1;
         a[1][6]=a[6][1]=1;
         a[2][6]=a[6][2]=1;
         a[4][6]=a[6][4]=1;
         a[6][5]=a[5][6]=1;
         int out=0;
         for(int i=1;i<=127;++i){
        
                change2(i);
           if(check()) out++;
         }
         cout<<out<<endl;//80
    return 0;}

### E ###

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80Mzk1OTc0Mw_size_16_color_FFFFFF_t_70 5]

### F ###

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80Mzk1OTc0Mw_size_16_color_FFFFFF_t_70 6]

#include<bits/stdc++.h>
    using namespace std;
    int main(){
        
        int n,a[1005],sum=0;
        cin>>n;
        for(int i=0;i<n;++i){
        
            scanf("%d",&a[i]);
            sum+=a[i];
        }
        sort(a,a+n);//默认升序排列
        int minn=a[0];
        int maxx=a[n-1];
        double av=sum/n;
        cout<<maxx<<endl;
        cout<<minn<<endl;
        printf("%.2f",av);
    }

### G ###

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