剑指Offer02 替换空格

/*************************************************************************
    > File Name: 02_Replace_Blank.c
    > Author: Juntaran
    > Mail: JuntaranMail@gmail.com
    > Created Time: 2016年08月24日 星期三 01时28分33秒
 ************************************************************************/

#include <stdio.h>

void ReplaceBlank(char* str)
{
    if (str==NULL)
    {
        return;
    }
    
    int blankCount = 0;
    int alphaCount = 0;
    int i = 0;
    while (str[i] != '\0')
    {
        if (str[i] == ' ')
            blankCount ++;
        alphaCount ++;
        
        i ++;
    }
    printf("alphaCount is %d\n", alphaCount);
    printf("blankCount is %d\n", blankCount);
    
    int newLength = alphaCount + 2*blankCount;
    printf("newLength is %d\n", newLength);
    int p1 = alphaCount + 1;
    int p2 = newLength + 1;
    while (p1>=0 && p2>p1)
    {
        if (str[p1] == ' ')
        {
            str[p2--] = '0';
            str[p2--] = '2';
            str[p2--] = '%';
        }
        else
        {
            str[p2--] = str[p1];
        }
        p1 --;
    }
}

int main()
{
    char str[] = "We are Happy!";
    printf("Before: %s\n", str);
    ReplaceBlank(str);
    printf("After: %s\n", str);
}