实验五

#include <stdio.h> 
const int N=3;
int main() {
    int a[N] = {1, 2, 3};  
    int i;    
    printf("通过数组名及下标直接访问数组元素:\n");
    for(i=0;i<N;i++)
        printf("%d: %d\n",&a[i],a[i]);        
    printf("通过地址间接访问数组元素:\n");
    for(i=0;i<N;i++)
        printf("%d: %d\n",a+i,*(a+i));
    return 0;
} 

1、是连续存放

2、等价

#include <stdio.h>
const int LINE = 2;
const int COL = 3;

int main() {
    int a[LINE][COL] = {1,2,3,4,5,6};  
    int i,j;
    
    printf("通过数组名及下标直接访问数组元素:\n");
    for(i=0; i<LINE; i++)
        for(j=0; j<COL; j++)
            printf("%d: %d\n", &a[i][j], a[i][j]);
        
    printf("通过地址间接访问数组元素:\n");
    for(i=0; i<LINE; i++)
        for(j=0; j<COL; j++)
            printf("%d: %d\n", a[i]+j, *(a[i]+j));
    
    printf("二维地址中a+i表示的地址:\n");
    for(i=0; i<LINE; i++) 
        printf("a + %d: %d\n", i, a+i);
    
    return 0;
} 

1、是按行存放

2、等价

3、等价

#include <stdio.h> 
#include <stdlib.h> 
const int N=3;
int main() {
    int a[N];
    int *p,i;
    for(p=a; p<a+N; p++)
        scanf("%d", p);
    for(p=a; p<a+N; p++)
        printf("%d ", *p);
    printf("\n");    
    p = a;
    for(i=0; i<N; i++)
        scanf("%d", p+i); 
    for(i=0; i<N; i++)
        printf("%d ", *(p+i));
    printf("\n"); 
    return 0;
} 

1、11-18行指向不确定地址，22-27行指向数组第一个元素地址

2、a[3],a[3]

3、a[0],a[0]

#include <stdio.h> 
int main() {
    int a[2][3] = {1,2,3,4,5,6};
    int i,j;
    int *p;  
    int (*q)[3]; 

    for(p=a[0]; p<a[0]+6; p++)
        printf("%d ", *p);
    printf("\n");
    
    for(q=a; q<a+2; q++)
        for(j=0; j<3; j++)
            printf("%d ", *(*q+j));
    printf("\n");
    return 0;
}

1、可以

2、表示该行第j+1个元素的地址；第j+1个元素的值

4、ABCDEFG

#include  <stdio.h>
const int 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 (item==x[mid])
            return mid;
        else if(item<x[mid])
            high = mid - 1;
        else
            low = mid + 1;
    }
    
    return -1;
}

#include  <stdio.h>

const int 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 ( item == *(x+mid) )
            return mid; 
        else if(item < *(x+mid))
            high=mid-1; 
        else
            low=mid+1; 
    }
    
    return -1;
}

#include <stdio.h>
#include<string.h> 
const int 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 temp[20];
    for(i=0;i<=n-1;i++) {
        k=i;
        for(j=i+1;j<=n-1;j++){
            if(strcmp(str[j],str[k])<0)
            k=j;
        }
        if(k!=i){
            strcpy(temp,str[i]);
            strcpy(str[i],str[k]);
            strcpy(str[k],temp);
        }
    }
}