/* evalf2.c (yukino.c) - Don Yang (uguu.org)
   Preprocess step 2: evaluate constants.

   11/05/99
                                                                           */

#include<stdio.h>
#include<string.h>
#include<math.h>

#define isdigit0(x)              (((x) >= '0' && (x) <= '9') || (x) == '.')

char *label[19] = {
   "-", "+", "%", "/", "*", "-", "exp", "ln", "log",
   "atan", "acos", "asin", "tan", "cos", "sin", "^", "(", "e", "PI"};

char expression[2048 + 1];
int expindex, lasttoken, lastop, nestlevel;

double operand[2048], lit;
int operator[2048];
int left[2048], right[2048], parent[2048];
int newnode, cursor;

int i;

double evaluate(int node)
{
   switch( operator[node] )
   {
      case 294:
         return atan2(0, -1);
      case 278:
         return exp(1);
      case 262:
         return evaluate(right[node]);
      case 245:
         return pow(evaluate(left[node]), evaluate(right[node]));
      case 228:
         return sin(evaluate(right[node]));
      case 212:
         return cos(evaluate(right[node]));
      case 196:
         return tan(evaluate(right[node]));
      case 180:
         return asin(evaluate(right[node]));
      case 164:
         return acos(evaluate(right[node]));
      case 148:
         return atan(evaluate(right[node]));
      case 132:
         return log10(evaluate(right[node]));
      case 116:
         return log(evaluate(right[node]));
      case 100:
         return exp(evaluate(right[node]));
      case 83:
         return -evaluate(right[node]);
      case 66:
         return evaluate(left[node]) * evaluate(right[node]);
      case 50:
         return evaluate(left[node]) / evaluate(right[node]);
      case 34:
         return fmod(evaluate(left[node]), evaluate(right[node]));
      case 17:
         return evaluate(left[node]) + evaluate(right[node]);
      case 1:
         return evaluate(left[node]) - evaluate(right[node]);
      default:
         return operand[node];
   }

}

void insertbop(int op)
{
   printf("%s ", label[op >> 4]);

   for(; operator[parent[cursor]] != 262 &&
         (operator[parent[cursor]] & 7) >= (op & 7);
         cursor = parent[cursor]);

   operator[newnode] = op;

   left[newnode] = cursor;
   parent[newnode] = parent[cursor];
   parent[cursor] = newnode;
   right[parent[newnode]] = newnode;
   cursor = newnode;

   newnode++;
   lasttoken = 0;
   lastop = 0;

}

void insertuop(int op)
{
   if( lasttoken == 1 )
      insertbop(66);
   if( op == 310 )
   {
      printf("%lG ", lit);
      lasttoken = 1;
   }
   else if( op == 294 || op == 278 )
   {
      printf("%s ", label[op >> 4]);
      lasttoken = 1;
   }
   else
   {
      if( op == 262 )
      {
         nestlevel++;
         if( lastop )
            putchar(8);
      }
      printf("%s", label[op >> 4]);
      lasttoken = 0;
   }
   lastop = 0;
   if( op >= 100 && op <= 228 )
   {
      putchar(32);
      lastop = 1;
   }

   operator[newnode] = op;
   operand[newnode] = lit;

   parent[newnode] = cursor;
   right[cursor] = newnode;
   cursor = newnode;

   newnode++;

}

int main(int argc, char *argv[])
{
   if( argc == 1 )
   {
      puts("?");
      return 0;
   }

   expindex = 0;
   strcpy(expression, argv[1]);
   for(i = 2; i < argc; i++)
      strcat(expression, argv[i]);
   strlwr(expression);


   operator[cursor = 0] = 262;
   newnode = 1;


   for(expindex = lasttoken = nestlevel = 0; expression[expindex];)
   {
      if( isdigit0(expression[expindex]) )
      {
         sscanf(expression + expindex, "%lf", &lit);

         insertuop(310);

         for(; isdigit0(expression[expindex]); expindex++);
         if( expression[expindex] == 101 )
         {
            if( expression[expindex + 1] == 43 || expression[expindex + 1] == 45 )
               expindex++;

            for(expindex++;
                expression[expindex] >= 48 && expression[expindex] <= 57;
                expindex++);
         }
      }
      else if( expression[expindex] > 97 && expression[expindex] <= 116 )
      {

         if( !memcmp(expression + expindex, label[14], 3) )      insertuop(228);
         else if( !memcmp(expression + expindex, label[13], 3) ) insertuop(212);
         else if( !memcmp(expression + expindex, label[12], 3) ) insertuop(196);
         else if( !memcmp(expression + expindex, label[6], 3) ) insertuop(100);
         else if( !memcmp(expression + expindex, label[8], 3) ) insertuop(132);
         else
         {
            if( !memcmp(expression + expindex, "pi", 2) )      insertuop(294);
            else if( !memcmp(expression + expindex, "ln", 2) ) insertuop(116);
            else
            {
               if( expression[expindex] == 101 )
                  insertuop(278);
               expindex--;
            }
            expindex--;
         }
         expindex += 3;
      }
      else if( expression[expindex] == 97 )
      {
         if( !memcmp(expression + expindex + 1, label[14], 3) )        insertuop(180);
         else if( !memcmp(expression + expindex + 1, label[13], 3) )   insertuop(164);
         else if( !memcmp(expression + expindex + 1, label[12], 3) )   insertuop(148);
         else expindex -= 3;
         expindex += 4;
      }
      else
      {
         i = expression[expindex++];
         if( lasttoken == 1 )
         {
            if( i == 40 )
            {
               insertuop(262);
            }
            else if( i == 41 && nestlevel )
            {
               printf("\b) ");
               for(cursor = parent[cursor]; operator[cursor] != 262; cursor = parent[cursor]);
               nestlevel--;
            }
            else
            {
               if( i == 42 )       insertbop(66);
               else if( i == 47 )  insertbop(50);
               else if( i == 37 )  insertbop(34);
               else if( i == 43 )  insertbop(17);
               else if( i == 45 )  insertbop(1);
               else if( i == 94 )  insertbop(245);
            }
         }
         else
         {
            if( i == 40 )       insertuop(262);
            else if( i == 45 )  insertuop(83);
         }
      }
   }

   if( lasttoken == 0 )
   {
      lit = 0;
      insertuop(310);
   }
   for(i = !putchar(8); i < nestlevel; i++)
      putchar(41);


   putchar(10);
   printf("\n= %.16lG\n", evaluate(0));

   return 0;

}