From 827f624def0ca86f5295ba3568a9c5bb9c7cd944 Mon Sep 17 00:00:00 2001
From: ZakyHermawan <zaky.hermawan9615@gmail.com>
Date: Mon, 14 Jun 2021 10:15:06 +0700
Subject: [PATCH] add infix to postfix conversion
---
infixToPostfixConversion.c | 105 +++++++++++++++++++++++++++++++++++++
1 file changed, 105 insertions(+)
create mode 100644 infixToPostfixConversion.c
diff --git a/infixToPostfixConversion.c b/infixToPostfixConversion.c
new file mode 100644
index 0000000..0be8fce
--- /dev/null
+++ b/infixToPostfixConversion.c
@@ -0,0 +1,105 @@
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+typedef struct Node {
+ char data;
+ struct Node* before;
+} Node;
+
+Node* push(Node* node, char data) {
+ Node* new = (Node*)malloc(sizeof(Node));
+ new->data = data;
+ new->before = node;
+
+ return new;
+}
+
+Node* pop(Node* node) {
+ if(node == NULL) {
+ return node;
+ }
+ Node* ptr = node;
+ node = node->before;
+ free(ptr);
+ return node;
+}
+
+Node* erase(Node* node) {
+ if(node == NULL) {
+ return NULL;
+ }
+ while(node->before != NULL) {
+ Node* ptr = node;
+ node = node->before;
+ free(ptr);
+ }
+
+ free(node);
+ node = NULL;
+ return node;
+}
+
+int precedence(char c) {
+ if(c == '+' || c == '-') return 1;
+ else if(c == '*' || c == '/' || c == '%') return 2;
+ else return 0;
+}
+
+int main() {
+ char exp[1000];
+ char hasil[1000];
+ for(int i=0; i<1000; ++i) hasil[i] = 0;
+ printf("Enter an expression: ");
+ scanf("%s", exp);
+ size_t len = strlen(exp);
+ exp[len] = ')';
+ exp[len+1] = 0;
+ int idx = 0;
+ int i_hasil = 0;
+ Node* stack = NULL;
+ stack = push(stack, '(');
+
+ while(idx != len+1) {
+ char now = exp[idx++];
+ printf("%s\n", hasil);
+ if(now == '(') {
+ stack = push(stack, now);
+ }
+ else if(now == '+' || now == '-' || now == '*' || now == '/' || now == '%') {
+ while(1) {
+ int now_pres = precedence(now);
+ int stack_pres = precedence(stack->data);
+ if(stack_pres >= now_pres) {
+ hasil[i_hasil++] = stack->data;
+ stack = pop(stack);
+ }
+ else {
+
+ stack = push(stack, now);
+ break;
+ }
+ }
+
+ }
+ else if(now == ')') {
+ char operator = stack->data;
+ while(operator != '(') {
+ hasil[i_hasil++] = operator;
+ stack = pop(stack);
+ operator = stack->data;
+ }
+ stack = pop(stack);
+ }
+ else {
+ hasil[i_hasil++] = now;
+ }
+ }
+ while(stack != NULL) {
+ char now = stack->data;
+ if(now == '(') break;
+ hasil[i_hasil++] = stack->data;
+ stack = pop(stack);
+ }
+ printf("%s\n", hasil);
+}
\ No newline at end of file
--
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