剑指offer--面试题5：替换空格

#include "stdio.h"/*length 为字符数组string的总容量*/void ReplaceBlank(char string[], int length){    if(string == NULL || length <= 0)        return;    int original_Length = 0;    //字符串string的实际长度    int number_Of_Blank = 0;   //空格数量       for(int i=0;string[i] != '\0';i++)    {        ++ original_Length;        if(string[i] == ' ')            ++ number_Of_Blank;    }    /*newLength 为把空格替换成'%20'之后的长度*/    int new_Length = original_Length + number_Of_Blank * 2;    if(new_Length > length)        return;    int index_Of_Original = original_Length;    int index_Of_New = new_Length;    while(index_Of_Original >= 0 && index_Of_New > index_Of_Original)    {        if(string[index_Of_Original] == ' ')        {            string[index_Of_New --] = '0';            string[index_Of_New --] = '2';            string[index_Of_New --] = '%';        }        else                   string[index_Of_New --] = string[index_Of_Original];          -- index_Of_Original;    }}int main()  {      char str[30]="we are happy.";      ReplaceBlank(str,30);      printf("%s\n",str);       return 0;  }