字符串练习题

11、求子字符串”cdf”在父串中出现的次数“11cfbks34cdf2ghacdf11”

#include <stdio.h>
#include<string.h>
int main(int argc, const char * argv[]) {

    char str[40] = "11cfbks34cdf2ghacdf11";
    char str1[40] = "cdf";
    int count = 0;
    int i = 0, j = 0;
    while(i < strlen(str))
    {
        if(str1[j] == str[i])
        {
            if(j == (int)strlen(str1)- 1 )
                count++;
            else
                j++;           
        }
        else
        {
            j = 0;            
        }          
        i++;
    }
    printf("子串cdf在父串中出现的次数为：%d次\n",count);    
    return 0;
}

10、自定义函数判断字符串是否是回文? 如:asdfdsa是回文、asds不是回文

*#include <stdio.h>*
*#include<string.h>*
int main(int argc, const char * argv[]) {
    char str[40];
    scanf("%s",str);
    int i = 0;
    int len = (int)strlen(str);
    while(i < len)
    {
        if(str[i] == str[len-1])
        {
            i++;
            len--;
        }
        else
        {
            printf("不是回文！\n");
            break;
        }        
    }
    if(i >= len)
        printf("是回文！\n");
   return 0;
}

//8、自定义函数连接字符串？

*#include <stdio.h>
*#include<string.h>**
char* conn(char *dest,const char *src);
int main(int argc, const char * argv[]) {
    char *str = "world";
    char dest[40] = "hello ";
    conn(dest,str);
    printf("连接后的字符串为：%s\n",dest);
    return 0;
}
char* conn(char *dest,const char *src)
{
    char *add = dest+strlen(dest);
    while((*add++ = *src++) != '\0');
    return dest;
}