实验6

task1

 

#include <stdio.h>
#define N 5
int binarySearch(int *x, int n, int item); // 函数声明
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);
// 调用函数binarySearch()在数组a中查找指定数据项key,并返回查找结果给index
// 补足代码①
// ×××
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;
}

 

 

task2

 

#include <stdlib.h>
void fun(char *a)
{
/*****ERROR1********/
int i=0;
char *p = a;
/****ERROR2***/
while (*p == '*')
{
a[i] = *p;
i++;
p++;
}
while (*p)
{
/******ERROR3*******/
if (*p!= '*')
{
a[i] = *p;
i++;
}
p++;
}
/******ERROR4*******/
a[i] = '\0';
}
int main()
{
char s[81];
printf("Enter a string :\n");
gets(s);
/***ERROR5******/
fun(s);
printf("The string after deleted:\n");
puts(s);
return 0;
}

 

 

task3

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
void fun(char *a)
{
    /**ERROR******/
    int i=0;
    char *t = a, *f = a;
    char *q = a;

    while (*t)
        t++;
    t--;

    while (*t == '*')
        t--;

    while (*f == '*')
        f++;
        
    /***ERROR***/
    while (q < f)
    {
        a[i] = *q;
        q++;
        i++;
    }

    while (q < t)
    {
        /***ERROR**/
        if (*q!= '*')
        {
            a[i] = *q;
            i++;
        }
        q++;
    }

    while (*q)
    {
        a[i] = *q;
        i++;
        q++;
    }

    /**ERROR**/
    a[i] = '\0';
}

int main()
{
    char s[81];

    printf("Entre a string:\n");
    gets(s);
    /**ERROR**/
    fun(s);
    printf("The sting after deleted:\n");
    puts(s);

    return 0;
}

 

 

task4

#include <stdio.h>
#include <string.h>

#define N 80
int isPalindrome(char *s);      // 函数声明

int main()
{
    char str[N];
    int flag;

    printf("Enter a string:\n");
    gets(str);

    flag = isPalindrome(str);   // 函数调用

    if (flag)
        printf("YES\n");
    else
        printf("No\n");

    return 0;
}

// 函数定义
// 功能：判断指针s指向的字符串是否是回文串，如果是，返回1；否则，返回0。
int isPalindrome(char *s)
{
    int a, b;
    b=strlen(s);
    b--;
    for(a=0;a<b&&s[a]==s[b];a++,b--)
    if(a>=b)
    return 0;
    else
    return 1;
}

6- task5

#include <stdio.h>
#define N 80
int count(char *str, char *substr); // 函数声明
int main()
{
char str[N], substr[N];
int n;
gets(str); // 输入母串
gets(substr); // 输入子串
n = count(str, substr); // 函数调用
printf("%d\n", n);
return 0;
}
int count(char *str, char *substr)
{
int i, j, k;
int num = 0;
for(i=0; str[i]!=0; ++i)
for(j=i, k=0; substr[k] == str[j]; k++, j++)
if(substr[k+1] == '\0')
{
num++;
break;
}
return(num);
}