add 4.10

1 files changed, 124 insertions, 0 deletions

diff --git a/4.10.c b/4.10.c
new file mode 100644
index 0000000..5128541
--- /dev/null
+++ b/4.10.c
@@ -0,0 +1,124 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <math.h>
+
+#define MAXLEN 1000
+#define MAXOP 100
+#define NUMBER_SIG '0'
+
+unsigned sneed_getline(char str[], unsigned len);
+double pop(void);
+void push(double input);
+char getop(char str[], char op[], unsigned *spos);
+
+int 
+main(void)
+{
+  char str[MAXLEN];
+  unsigned len, spos;
+  char op[MAXOP];
+  double op2;
+
+  while ((len = sneed_getline(str, MAXLEN)) > 1) {
+    spos = 0;
+    while (spos < len) {
+      switch (getop(str, op, &spos)) {
+        case '0' :
+          push(atof(op));
+          break;
+        case '+' :
+          push(pop() + pop());
+          break;
+        case '*' :
+          push(pop() * pop());
+          break;
+        case '-' :
+          op2 = pop();
+          printf("hey: %g\n", op2);
+          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: unknow command\n");
+      }
+    }
+
+    printf("%.8g\n", pop());
+  }
+
+  return 0;
+}
+
+unsigned 
+sneed_getline(char str[], unsigned len)
+{
+  char input;
+  unsigned i;
+
+  for(i = 0; i < len+1 && (input = getchar()) != EOF && input != '\n'; i++)
+    str[i] = input;
+
+  str[i] = '\0';
+
+  return i;
+}
+
+#define MAXVAL 100 
+double val[MAXVAL];
+int sp = 0;
+
+double 
+pop(void)
+{
+  if (sp > 0)
+    return val[--sp];
+  else 
+    printf("Err: stack empty\n");
+
+  return 0.0;
+}
+
+void
+push(double input)
+{
+  if (sp < MAXVAL)
+    val[sp++] = input;
+  else 
+    printf("Err: stack full\n");
+}
+
+char 
+getop(char str[], char op[], unsigned *spos)
+{
+  int j;
+  
+  /* skip blanks */
+  for (; isblank(str[*spos]); (*spos)++)
+    ;
+
+  /* return operator */
+  if (!isdigit(str[*spos]) &&  str[*spos] != '.') {
+    return str[(*spos)++];
+  }  
+
+  /* collect digit s*/
+  for (j = 0; j < MAXOP+1 && (isdigit(str[*spos]) || str[*spos] == '.'); j++, (*spos)++)
+    op[j] = str[*spos]; 
+
+  op[*spos] = '\0';
+
+  return NUMBER_SIG;
+}