实验五

#include<stdio.h>
#define N 5
void output(int x[], int n);
int main()
{
    int x[N] = { 9,55,30,27,22 };
    int i, t,k;
    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");
}

 

 

#include<stdio.h>
#define N 5
void output(int x[], int n);
int main()
{
    int x[N] = { 9,55,30,27,22 };
    int i, t,k;
    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");
}

 

 

#define _CRT_SECURE_NO_WARNINGS
#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("输入带查找的数据项:");
    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;
}

 

 

#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#define N 5
void selectSort(int a[], int n); 
void input(int a[], int n); 
void output(int a[], int n);
int main()
{
    int a[N];
    printf("输入%d个整数\n", N);
    input(a, N);
    printf("排序前的数据：\n");
    output(a, N);
    selectSort(a, N);
    printf("排序后的数据:\n");
    output(a, N);
    return 0;
}
void input(int a[], int n)
{
    int i;
    for (i = 0; i < n; i++)
        scanf("%d", &a[i]);
}
void output(int a[], int n)
{
    int i;
    for (i = 0; i < n; i++)
        printf("%d ", a[i]);
    printf("\n");
}
void selectSort(int a[], int n)
{
    int i, j, k, temp;
    for (i = 0; i < n - 1; i++)
    {
        k = i;
        for (j = i + 1; j < n; j++)
            if (a[j] < a[k])
                k = j;
        if (k != i)
        {
            temp = a[i];
            a[i] = a[k];
            a[k] = temp;
        }
    }
}

 

 

#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;
}

 

 

#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,*(a+%d)=%d\n", i, a + i, i, *(a + i));
    return 0;
}