替换空格：请实现一个函数，把字符串中的每个空格替换成“%20”

void replaceBlank(char *src,int length)
{
    int oriLength = 0;
    int countBlank = 0;
    int i = 0;
    if (src == NULL && length <= 0)
    {
        return;
    }
    // 统计总长度和空格数
    while (src[i] != ‘\0‘)
    {
        oriLength++;
        if(src[i] == ‘ ‘)
        {
            countBlank++;
        }
        i++;
    }

    int newLength = oriLength + 2*countBlank;

    // 新长度是否超限制
    if (newLength > length)
    {
        return;
    }
    // 拷贝
    int indexOri = oriLength;
    int indexNew = newLength;
    while (indexOri >= 0 && indexNew > indexOri)
    {
        if (src[indexOri] == ‘ ‘)
        {
            src[indexNew--] = ‘0‘;
            src[indexNew--] = ‘2‘;
            src[indexNew--] = ‘%‘;
        }
        else
        {
            src[indexNew--] = src[indexOri];
        }
        indexOri--;
    }
    printf("newstr= %s\n",src);
}