diff options
Diffstat (limited to '4')
| -rw-r--r-- | 4/6.c | 28 |
1 files changed, 13 insertions, 15 deletions
@@ -11,15 +11,15 @@ #define VARIABLE '3' /* signal that a variable was found */ #define MAXVAL 100 /* max depth of val and var stack */ #define BUFSIZE 100 -#define VARCOUNT 51 /* supported variable count */ +#define VARCOUNT 52 /* supported variable count */ #define LASTPRINT 'L' /* variable for most recently printed val */ +#define INDEX(x) (x <= 'Z' ? x - 'A' : x - 71) + int sp = 0; /* next free stack position */ double val[MAXVAL]; /* value stack */ double L = 0; -int vidx = 0; /* variable array position */ -char varn[VARCOUNT]; /* variable name array */ double varv[VARCOUNT]; /* variable value array */ int bufp = 0; /* next free position in buf */ @@ -42,7 +42,7 @@ void clear(); /* adds support for sin, exp and pow functions */ int main(int argc, char *argv[]) { - int type, i, var; + int type, i; double op2, op1; char s[MAXOP]; @@ -101,24 +101,22 @@ int main(int argc, char *argv[]) { if (s[0] == 'L') printf("error: reserved variable %c\n", s[0]); else { - varn[vidx] = s[0]; - varv[vidx++] = pop(); + i = INDEX(s[0]); + if (i < 0 || i > VARCOUNT - 1) + printf("error: unknown symbol %s\n", s); + else + varv[i] = pop(); } break; case VARIABLE: if (s[0] == 'L') printf("last printed: %.8g\n", L); else { - var = 0; - for (i = 0; i < vidx; i++) { - if (varn[i] == s[0]) { - var = 1; - push(varv[i]); - break; - } - } - if (!var) + i = INDEX(s[0]); + if (i < 0 || i > VARCOUNT - 1) printf("error: unknown symbol %s\n", s); + else + push(varv[i]); } break; case '\n': |