5.10

1 files changed, 92 insertions, 0 deletions

diff --git a/5.10.c b/5.10.c
new file mode 100644
index 0000000..26a9f84
--- /dev/null
+++ b/5.10.c
@@ -0,0 +1,92 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <math.h>
+
+#define MAXOP 1000
+#define NUMBER_SIG '0'
+
+double ops[MAXOP];
+int opsl = 0;      /* ops location */
+
+char getop(char str[]);
+double pop(void);
+void push(double num);
+
+int 
+main(int argc, char *argv[])
+{
+  int opnum;
+  double op2;
+  char input;
+
+  for (opnum = 1; --argc; opnum++)
+    switch ((input = getop(argv[opnum]))) {
+      case NUMBER_SIG :
+        push(atof(argv[opnum]));
+        break;
+      case '*' :
+        push(pop() * pop());
+        break;
+      case '+' :
+        push(pop() + pop());
+        break;
+      case '-' :
+        op2 = pop();
+        push(pop() - op2);
+        break;
+      case '/' :
+        if ((op2 = pop()) == 0.0)
+          printf("Err: deviser cant be zero\n");
+        else 
+          push(pop() / op2);
+        break;
+      case '%' :
+        op2 = pop();
+        if (op2 != 0)
+          push(fmod(pop(), op2));
+        else 
+          printf("Err: deviser cant be zero\n");
+        break;
+      default :
+        printf("Err: unknown command %d-'%c'\n", input, input);
+        break;
+    }
+
+  printf("Result: %.8g\n", pop());
+
+  return 0;
+}
+
+char 
+getop(char str[])
+{
+  /* skip blanks */
+  while (isblank(*str))
+    str++;
+
+  /* return operators */
+  if (!isdigit(*str) && *str != '.' && !isdigit(*(str+1)))
+    return *str;
+
+  /* collect numbers */
+  else if (isdigit(*str) || *str == '.')
+    return NUMBER_SIG;
+
+  return -1;
+}
+
+double 
+pop(void)
+{
+  return (opsl > 0) ? ops[--opsl] : 0 ;
+}
+
+void
+push(double num)
+{
+  if (opsl <= MAXOP) 
+    ops[opsl++] = num;
+  else 
+    printf("Err: stack full\n");
+}