Вот вроде работает. Не выполняет таких действий 2+(-3) как можно сделать?
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <ctype.h>
#include <assert.h>
#include <iostream>
int tok;
int flag;
double b, a,m, n, h, h0, f,y,i, t;
double tokval, x;
int next() {
for (;;) {
int c = getchar();
if (c == EOF || strchr("kws+-*/^()\n", c) != NULL) return tok = c;
//if (strchr("m",c)) c=a+'0';
if (isspace(c)) continue;
if (isdigit(c) || c == '.'|| c=='v'|| c=='s'|| c=='w'|| c=='k'|| c=='m') {
ungetc(c, stdin);
scanf(" %lf", &tokval);
return tok = 'n';
}
fprintf(stderr, "Bad character: %c\n", c); abort();
}
}
void skip(int t) { assert(tok == t); next(); }
double kor();
// numpar ::= number | '(' expr ')'
double numpar() {
if (tok == 'n') { double x = tokval; skip('n'); return x; }
skip('('); double x = kor(); skip(')'); return x;
}
// factor ::= numpar | numpar '^' factor
double factor() {
double x = numpar();
if (tok == '^') { skip('^'); x = pow(x, factor()); }
return x;
}
// term ::= factor | term '*' factor | term '/' factor
double term() {
double x = factor();
for (;;) {
if (tok == '*') { skip('*'); x *= factor(); }
else if (tok == '/') { skip('/'); x /= factor(); }
else return x;
}
}
// expr ::= term | expr '+' term | expr '-' term
double expr() {
double x = term();
for (;;) {
if (tok == '+') { skip('+'); x += term(); }
else if (tok == '-') { skip('-'); x -= term(); }
else return x;
}
}
double sinn(){
double x= expr();
for(;;){
if (tok == 's') { skip('s'); x = sin(expr());}
return x;
}
}
double coss(){
double x= sinn();
for(;;){
if (tok == 'w') { skip('w'); x = cos(sinn());}
return x;
}
}
double kor() {
double x = coss();
if (tok == 'k') { skip('k'); x = sqrt(coss()); }
return x;
}
int main() {
next();
while (tok != EOF) {
if (tok == '\n') { skip('\n'); continue; }
printf("%.9g\n", kor());
}
return 0;
}