// 文字列式計算エンジン
// 1998 N.Inoue
//

public class Calc
{
	private final static String FUNCTION[] = {"sin", "cos", "tan", "log"};
	private final static int FI_SIN = 0;
	private final static int FI_COS = 1;
	private final static int FI_TAN = 2;
	private final static int FI_LOG = 3;
	private final static int MAX_FI = 3;
	
	/**
	 * 定数の式を計算して答えを返す
	 * @param str 式
	 */
	static public double calc(String str)
	{
		return calc(str, 0);
	}
	
	/**
	 * 文字の入った式で、文字の値を代入して計算して答えを返す
	 * @param str 文字の式
	 * @param v 文字の値
	 * @param c 文字
	 */
	static public double calc(String str, double v, char c)
	{
		StringBuffer strbuf = new StringBuffer(str);
		int strlen = str.length();
		for(int i=0; i<strlen; i++)
			if(str.charAt(i) == c)
				if((i == 0)||(!isLowerAlpha(str.charAt(i-1))))
					if((i == strlen-1)||(!isLowerAlpha(str.charAt(i+1))))
						strbuf.setCharAt(i, 'x');
		return calc(new String(strbuf), v);
	}
	
	static private boolean isLowerAlpha(char c)
	{
		if((c >= 'a')&&(c <= 'z')) return true; else return false;
	}
	/**
	 * ｘの入った式で、ｘの値を代入して計算して答えを返す
	 * @param str ｘの式
	 * @param x ｘの値
	 */
	static public double calc(String str, double x)
	{
		double answer = 0.0;
		double number = 0.0;
		double kou = 1.0;
		double jkou = 1.0;
		boolean jou = false;
		char cchr = '*';
		int decimal = 0;
		int plusminus = 1;
		int strpos = 0;
		int kdepth = 0;
		int startpos = 0;
		
		// 空文字列の答えは０を返す
		if(str.length() == 0) return 0.0;
		
		// 関数を数値に変換
		String funcstr;
		String numstr;
		int sl;
		for(int i = 0; i <= MAX_FI; i++)
		{
			funcstr = FUNCTION[i];
			sl = funcstr.length();
			while((startpos = str.indexOf(funcstr)) != -1)
			{
			  	strpos = startpos + sl;
			  	kdepth = 1;
			  	do
			  	{
		  			strpos++;
		  			if(str.charAt(strpos) == '(')
		  				kdepth++;
			  		else if(str.charAt(strpos) == ')')
			  			kdepth--;
			  	}while(kdepth > 0);
				switch(i)
				{
				  case FI_SIN:
					number = Math.sin(calc(str.substring(startpos+sl+1, strpos), x));
				  	break;
				  case FI_COS:
					number = Math.cos(calc(str.substring(startpos+sl+1, strpos), x));
				  	break;
				  case FI_TAN:
					number = Math.tan(calc(str.substring(startpos+sl+1, strpos), x));
				  	break;
				  case FI_LOG:
					number = Math.log(calc(str.substring(startpos+sl+1, strpos), x));
				  	break;
				  default:
				  	number = 0.0;
				}
				numstr = Double.toString(number);
				if(number<0)
					numstr = "(" + numstr + ")";
				str = str.substring(0, startpos) + numstr + str.substring(strpos+1);
			}
		}
		
		// 式の読解と計算
		strpos = 0;
		number = 0.0;
		do
		{
			if(Character.isDigit(str.charAt(strpos)))
			{
				if(decimal<0)
				{
					number = number + Character.digit(str.charAt(strpos), 10)*Math.pow(10, decimal);
					decimal--;
				}
				else
					number = number*10 + Character.digit(str.charAt(strpos), 10);
				continue;
			}
			else switch(str.charAt(strpos))
			{
			  case 'x':
			  	number = x;
			  	continue;
			  case '(':
			  	kdepth = 1;
		  		startpos = strpos;
			  	do
			  	{
			  		strpos++;
			  		if(str.charAt(strpos) == '(')
			  			kdepth++;
			  		else if(str.charAt(strpos) == ')')
			  			kdepth--;
			  	}while(kdepth > 0);
		  		number = calc(str.substring(startpos+1, strpos), x);
			  	continue;
			  case '|':
		  		startpos = strpos;
			  	do strpos++; while(str.charAt(strpos) != '|');
		  		number = Math.abs(calc(str.substring(startpos+1, strpos), x));
			  	continue;
			  case '.':
			  	decimal = -1;
			  	continue;
			  case '+':
				answer = answer + plusminus*calcsub(kou, cchr, number, jou, jkou);
				number = 0.0;
				decimal = 0;
				plusminus = 1;
				kou = 1.0;
				cchr = '*';
				jou = false;
				continue;
			  case '-':
				answer = answer + plusminus*calcsub(kou, cchr, number, jou, jkou);
				number = 0.0;
				decimal = 0;
				plusminus = -1;
				kou = 1.0;
				cchr = '*';
				jou = false;
				continue;
			  case '*':
				kou = calcsub(kou, cchr, number, jou, jkou);
				cchr = '*';
				jou = false;
				number = 0.0;
				decimal = 0;
				continue;
			  case '/':
				kou = calcsub(kou, cchr, number, jou, jkou);
				cchr = '/';
				jou = false;
				number = 0.0;
				decimal = 0;
				continue;
			  case '^':
				if(jou)
					jkou = Math.pow(jkou, number);
				else
					jkou = number;
				jou = true;
			  	number = 0.0;
			  	decimal = 0;
			  	continue;
			}
		}while(str.length() > ++strpos);
		answer = answer + plusminus*calcsub(kou, cchr, number, jou, jkou);
		return answer;
	}
	
	final static double calcsub(double num_a, char chr, double num_b, boolean jou, double jkou)
	{
		if(!jou) switch(chr)
		{
		  case '*':
			return num_a * num_b;
		  case '/':
			return num_a / num_b;
		}
		else switch(chr)
		{
		  case '*':
			return num_a * Math.pow(jkou, num_b);
		  case '/':
			return num_a / Math.pow(jkou, num_b);
		}
		return 0;
	}
}