实验五

task1-1

#include <stdio.h>
#define N 5

void output(int x[], int n);

int main()
{
    int x[N] = {9, 55, 30, 27, 22};
    int i;
    int k;
    int t;
    
    printf("original array:\n");
    output(x,N);
    
    k=0;
    for(i=1;i<N;++i)
        if(x[i]>x[k])
            k=i;
            
    if(k != N-1)
    {
        t=x[N-1];
        x[N-1]=x[k];
        x[k]=t;
    }    
    
    printf("after swapped:\n");
    output(x,N);
    
    return 0;    
}

void output(int x[], int n)
{
    int i;
    
    for(i=0;i<n;++i)
        printf("%d",x[i]);
        
        printf("\n");
}

 

task1-2

#include <stdio.h>
#define N 5

void output(int x[], int n);

int main()
{
    int x[N] = { 9, 55, 30, 27, 22 };
    int i;
    int t;

    printf("original array:\n");
    output(x, N);

    for (i = 0; i < N - 1; ++i)
        if (x[i] > x[i + 1])
        {
            t = x[i];
            x[i] = x[i + 1];
            x[i + 1] = t;
        }

    printf("after swapped:\n");
    output(x, N);

    return 0;

}

    void output(int x[], int n)
    {
        int i;
        for (i = 0; i < n; ++i)
            printf("%d", x[i]);

        printf("\n");
    }

 

task1-1交换一次  task1-2交换3次

算法一只改变最大值和最后一个数据的位置

算法二将最大值后面的数据位置全改变了

 

task2

#include <stdio.h>

#define N 5

int binarySearch(int x[], int n, int item);

int main()
{
    int a[N]={2, 7, 19, 45, 66};
    int i, index, key;
    
    printf("数组a中的数据:\n");
    for(i=0;i<N;i++)
        printf("%d",a[i]);
    printf("\n");
    
    printf("输入待查找的数据: ");
    scanf("%d",&key);
    
    index=binarySearch(a,N,key);
    
    if(index>=0)
        printf("%d 在数组中，下标为%d\n",key,index);
    else
        printf("%d 不在数组中\n",key);    
        
    return 0;
}

int binarySearch(int x[], int n, int item)
{
    int low,high,mid;
    
    low=0;
    high=n-1;
    
    while(low<=high)
    {
        mid=(low+high)/2;
        
        if(x[mid]==item)
            return mid;    
        else if(x[mid]>item)
            high=mid-1;
        else
            low=mid+1;
    }
    return -1;
}

 

 

 

task 3-2

#include <stdio.h>
#include <string.h>
#define N 5

void selectSort(char str[][20], int n);

int main()
{
    char name[][20] = {"Bob","Bill","Joseph","Taylor","George"};
    int i;
    
    printf("输出初始名单:\n");
    for(i=0;i<N;i++)
        printf("%s\n",name[i]);
        
    selectSort(name,N);
    
    printf("按字典序输出名单:\n");
    for(i=0;i<N;i++)
        printf("%s\n",name[i]);
        
    return 0;
}

void selectSort(char str[][20], int n)
{
    int i,j,k;
    char t[20];
    
    for(i=0;i<n-1;i++)
    {
        k=i;
        
        for(j=i+1;j<n;j++)
            if(strcmp(str[j],str[k])<0)
                k=j;
                
        if(k!=i)
        {
            strcpy(t,str[i]);
            strcpy(str[i],str[k]);
            strcpy(str[k],t);
        }
    }
}

 

task 4

#include <stdio.h>

int main()
{
    int n;
    int *pn;
    
    n = 42;
    pn = &n;
    
    printf("&n = %#x,n = %d\n",&n,n);
    printf("&pn = %#x,pn = %#x\n",&pn,pn);
    printf("pn = %d\n",*pn);
    
    return 0;
}

 

n的地址是62fe1c  存放的数是42

pn的地址是62fe10 存放的是n的地址

间接访问的是n

 

task5

 

#include <stdio.h>
#define N 5

int main()
{
    int a[N] = {1, 9, 2, 0, 7};
    int i;
    int *p;
    
    for(i=0;i<N;++i)
        printf("&a[%d] = %#x, a[%d] = %d\n",i,&a[i],i,a[i]);
        
    printf("\n");
    
    for(i=0;i<N;++i)
        printf("a+%d = %#x, *(a+%d) = %d\n",i,a+i,i,*(a+i));
        
    printf("\n");
    
    p = a;
    for(i=0;i<N;++i)
        printf("p+%d = %#x, *(p+%d) = %d\n",i,p+i,i,*(p+i));
        
    return 0;
}

 可以

可以

标签：main,int,实验,printf,output,include,pn
来源： https://www.cnblogs.com/zhouyang0532/p/15680477.html