北理2017

#include<bits/stdc++.h>
#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <algorithm>
#include <vector>


using namespace std;

//1.让输入10个整数然后求出平均值之后与10个整数比较然后输出最接近平均数的整数
int main()
{
	int m = 10;
	int a[10];
	int res = 0;
	for(int i = 0; i<m;i++)
	{
		scanf("%d",&a[i]);
		res+=a[i];
	} 
	double avg = res/10.0;
	double min = abs(avg-a[0]);
	int flag = 0;
	for(int i = 0;i<m;i++)
	{
		double tmp = abs(avg - a[i]);
		if(min >  tmp)
		{
			min = tmp;
			flag = i;
		}
	}
	printf("%lf\n",avg);
	printf("%d",a[flag]);
	return 0;
}
//2.2001-2016中的素数
int main2()
{
	for(int i = 2001; i<=2016; i++)
	{
		int flag = 0;
		for(int j = 2;j<i;j++)
		{
			if(i % j == 0)
			{
				flag = 1;
				break;
			}
		}
		if(flag == 0)
		{
			printf("%d ",i);
		}
	}
    return 0;
}

//3.求n项之和
//1 2 4 7 11 16 21
int main3()
{
	int n;
	int res = 0;
	int x = 1;
	scanf("%d",&n);
	for(int i = 1;i<=n;i++)
	{
		res+=x;
		x+=i;
	}
	printf("%d",res);
	return 0;
	
} 

//4.递归方法输入n求2n!
int main4()
{
	int n;
	scanf("%d",&n);
	int res = 2*n;
	long long s = 1;
	for(int i = 1;i<=res;i++)
	{
		s = s*i;
	}
	printf("%d",s);
	
	return 0;	
} 


//建立一个双向循环链表，可以输入若干个整数，然后让你正向输出，逆向输出
typedef int ElemType;
typedef struct node
{
	ElemType data;
	struct node*pre;
	struct node*next;
}linkNode,*linkList;

//链表初始化
linkList initLinkList()
{
    linkList head=(linkList)malloc(sizeof(linkNode));
    if(!head)
    {
        printf("动态内存分配失败!\n");
        exit(0);
    }
    head->next=head;
    head->pre=head;

    printf("链表初始化成功!\n");
    return head;
}

linkList createNode(int val)
{
	linkList head=(linkList)malloc(sizeof(linkNode));
	head->data = val;
	head->pre = nullptr;
	head->next = nullptr;
	return head;
}


void insertLinkListByNext(linkList l,int x)
{
	linkList newNode = createNode(x);
	linkList lastNode = l;
	while(lastNode->next != l)
	{
		lastNode = lastNode->next;
	}
	l->pre = newNode;
	newNode->next = l;
	lastNode->next = newNode;
	newNode->pre = lastNode;
}

//正序输出 
void printList(linkList l)
{
	linkList p = l->next;
	while(p != l)
	{
		printf("%d",p->data);
		p = p->next;	
	}	
	printf("\n");
} 

//逆序输出
void printList_reverse(linkList l)
{
	linkList p = l->pre;
	while(p != l)
	{
		printf("%d",p->data);
		p = p->pre;	
	}	
	printf("\n");
} 

int main5()
{
	linkList head = initLinkList();
	insertLinkListByNext(head,1);
	insertLinkListByNext(head,2);
	insertLinkListByNext(head,4);
	insertLinkListByNext(head,3);
	insertLinkListByNext(head,5);
	printList(head);
	printList_reverse(head);
	
	
	return 0;
}