did some electronics and comp sci work

1 files changed, 73 insertions, 0 deletions

diff --git a/comp/work/37/rpn.c b/comp/work/37/rpn.c
new file mode 100644
index 0000000..aefd971
--- /dev/null
+++ b/comp/work/37/rpn.c
@@ -0,0 +1,73 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <math.h>
+
+#include "stack.h"
+
+int main(int argc, char **argv){
+	stack *s = initstack(0, 64);
+	char in[128] = {0};
+
+	if (argc > 1){
+		for (int i = 1; i < argc; i++){
+			strcat(in, argv[i]);
+			strcat(in, " ");
+		}
+	} else fgets(in, 128, stdin);
+
+	for (int i = 0; i < 128; i++) if (in[i] == '\n') in[i] = '\0';
+	fflush(stdin);
+
+	int r;
+
+	int a;
+	int b;
+
+	char *tok = strtok(in, " ");
+	while (tok != NULL){
+		switch (tok[0]) {
+			case '+':
+				a = s->pop(s);
+				b = s->pop(s);
+				s->push(s, b+a);
+				break;
+			case '-':
+				a = s->pop(s);
+				b = s->pop(s);
+				s->push(s, b-a);
+				break;
+			case '*':
+				a = s->pop(s);
+				b = s->pop(s);
+				s->push(s, b*a);
+				break;
+			case '/':
+				a = s->pop(s);
+				b = s->pop(s);
+				s->push(s, b/a);
+				break;
+			case '^':
+				a = s->pop(s);
+				b = s->pop(s);
+				s->push(s, pow(b, a));
+				break;
+			case '.': 
+				r = s->pop(s);
+				printf("%d\n", r);
+				break;
+			default:
+				s->push(s, atoi(tok));
+				break;
+		}
+		tok = strtok(NULL, " ");
+		if (tok == NULL){
+			r = s->pop(s);
+			printf("%d\n", r);
+			break;
+		}
+	}
+	s->free(s);
+	return 0;
+}