[字符串] Trim blank

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

void TrimBlank(char * s)
{
    if(NULL == s)
    {
        return ;
    }

    int iLen = strlen(s);
    if(iLen <= 0)
    {
        return ;
    }

    //trim left
    int i = 0;
    for (i = 0; i < iLen; i++)
    {
        if(s[i] != ' ')
        {
            break;
        }
    }
    if(i == iLen) //this means string is all blank
    {
        return ;
    }


    //trim right
    char * pcRight = &s[iLen - 1];
    while (*pcRight == ' ')
    {
        pcRight--;
    }
    *(pcRight+1) = '\0';


    //trim middle duplicate blank
    bool bInSpace = false;
    int iNewIndex = 0;
    char *pcStart = &s[i];
    iLen = strlen(pcStart);
    for (i = 0; i < iLen; i++)
    {
        if(pcStart[i] == ' ')
        {
            if(bInSpace)
            {
                continue;
            }
            else
            {
                s[iNewIndex++] = pcStart[i];
            }
            bInSpace = true;
        }
        else
        {
            s[iNewIndex++] = pcStart[i];
            bInSpace = false;
        }
    }
    s[iNewIndex] = '\0';
}

int main()
{
    char ac[] = "  This is   a happy   day    , only    ll ";
    TrimBlank(ac);
    printf("%s\n", ac);
    return 0;
}