字符串、数组相关经典编程题面试题

 

Implement an algorithm to determine if a string has all unique characters What if you can not use additional data structures? 

如何判断字符串中是否有重复的字符？

bool isUniqueChar(string s){    bool h[256]={0};    for (int i=0; i<=s.size()-1; ++i)    {        if (h[s[i]]) return false;        h[s[i]] = 1;    }    return true;}

 

 

如何将C的字符数组（char *）逆转？

Write code to reverse a C-Style String (C-String means that “abcd” is represented as five characters, including the null character ) 

 

void cStringReverse(char *s){    char *end = s;    char tmp;    if (s)    {        while (*end) ++end;        --end;        while (s < end)        {            *s++ = *end--;        }    }}

 

如何将字符数组重复的字符去除？不允许使用额外的存储空间。

Design an algorithm and write code to remove the duplicate characters in a string without using any additional buffer. NOTE: One or two additional variables are fine. An extra copy of the array is not.

 

void removeDuplicateChar(char *s){    char *end = s+1;    char *p = s+1;    if (s)    {        while (*p)        {            char *q = s;            while (q < p)            {                if (*p == *q)                {                    break;                }                ++q;            }            if (p == q)            {                *end = *p;                ++end;            }            ++p;        }        *end = '\0';    }}