CC1.4

public void replace(char[] line) {
		int len;					// original length;
		int cnt = 0;				// space count
		for(len = 0; line[len] != '\0'; len++)
		{
			if(line[len] == ' ')
				cnt++;
		}
		int new_len = len + cnt*2;	// length of new string
		int k = new_len - 1;		// starts from the end of new string
		for(int i = len - 1; i >= 0; i--)		// i starts from the end of original string
		{
			if(line[i] == ' ')
			{
				line[k] = '0';
				line[k-1] = '2';
				line[k-2] = '%';
				k -= 2;
			}
			else
				line[k] = line[i];
			k--;
		}
    }