实验五
任务1
#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("通过地址直接访问数组元素:\n");
for (i = 0; i <N; i++)
printf("%d,%d\n", a + i, *(a + i));
return 0;
}
#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;
}
#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;
}
答：是指向确定的地址；指向a[3]；指向a[0]。
任务4
#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;
}
答：可以；前者表示&a[0][j]地址；后者表示a[0][j]的值；ABCDEFG。
任务5
#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;
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;
}
#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;j++)
if(strcmp(str[k],str[j])>0)
k=j;
if(k != i)
{
strcpy(temp,str[i]);
strcpy(str[i],str[k]);
strcpy(str[k],temp);
}
}
}
