Create Infix_to_Postfix_Conversion_Using_Stack.c

Author: santhosh-programmer

Infix_to_Postfix_Conversion_Using_Stack.c

@@ -0,0 +1,70 @@
+// Give an input Infix Expression, write the program to convert the given infix expression to postfix expression using Stack Operations.
+
+// Input : Infix Expression
+
+// Output : Postfix Expression
+
+#include<stdio.h>
+#include<string.h>
+char s[20];
+int top=-1;
+int pri(char c)
+{
+    switch(c)
+    {
+        case '+':
+        case '-':return 1;
+                 break;
+        case '*':
+        case '/':return 2;
+                 break;
+        default: return 0;
+    }
+}
+void push(char c)
+{
+    top++;
+    s[top]=c;
+}
+char pop()
+{
+    int a=top;
+    top--;
+    return s[a];
+}
+int main()
+{
+    char str[20];
+    scanf("%[^\n]s",str);
+    for(int i=0;i<strlen(str);i++)
+    {
+        if(str[i]=='+'||str[i]=='-'||str[i]=='*'||str[i]=='/')
+        {
+            if(top==-1)
+            push(str[i]);
+            else
+            {
+                if(pri(s[top])>=pri(str[i]))
+                {
+                    printf("%c",pop());
+                    push(str[i]);
+                }
+                else
+                push(str[i]);
+            }
+        }
+        else if(str[i]=='(')
+        push(str[i]);
+        else if(str[i]==')')
+        {
+            while(s[top]!='(')
+            printf("%c",pop());
+            pop();
+        }
+        else if(str[i]>='a' && str[i]<='z')
+        printf("%c",str[i]);
+    }
+    while(top>=0)
+    printf("%c",pop());
+    return 0;
+}