added minimum bracket reversal needed to make brackets balanced expre…

…ssion

C/Data-Structures/STACKS/MISC-STACKS/minimum_bracket_reversal_for_balanced_expression.c

@@ -0,0 +1,131 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <math.h>
+
+/*MY OWN STACK*/
+char stack[50];
+int top=-1;
+
+/**
+ * isEmpty()
+ * tells if the stack is empty or not
+ * @return bool
+ **/
+bool isEmpty()
+{
+  return top==-1;
+}
+
+/**
+ * size()
+ * returns the size of the stack
+ * @return int
+ **/
+int size()
+{
+  return top+1;
+}
+
+/**
+ * push(char)
+ * push char to the top of the stack
+ **/
+void push(char ch)
+{
+  	stack[++top]=ch;
+}
+
+/**
+ * pop()
+ * deletes and returns the top element of the stack
+ * @return char
+ **/
+char pop()
+{
+  if(isEmpty())
+  {
+    return '0';
+  }
+  char temp = stack[top];
+  top--;
+  return temp;
+}
+
+/**
+ * peek()
+ * returns the top element of the stack
+ * @return char
+ **/
+char peek()
+{
+  return stack[top];
+}
+
+/**
+ * print()
+ * prints the stack
+ **/
+void print()
+{
+  for(int i=0;i<=top;i++)
+  {
+    printf("%c ",stack[i]);
+  }
+  printf("\n");
+}
+
+/*MAIN PROGRAM*/
+int main()
+{
+	int T;
+  	scanf("%d",&T);
+  	while(T-->0)
+    {
+      	char str[50];
+      	scanf("%s",str);
+      	if(strlen(str)%2)
+        {
+          printf("-1\n");
+        }
+      	else
+        {
+          //balancing the brackets
+          for(register int i=0;i<strlen(str);i++)
+          {
+            if(str[i]==']' && !isEmpty())
+            {
+              	if(peek()=='[')
+                {
+                  pop();
+                }
+              	else
+                {
+                  push(str[i]);
+                }
+            }
+            else
+            {
+              push(str[i]);
+            }
+          }
+            //checking balancing
+            //remaining left in the stack
+            //counting the brackets
+            int a=0; //'['
+            int len = size();
+          	while(!isEmpty() && peek()=='[')
+            {
+              pop();
+              a++;
+            }
+            int b=len-a;
+         	double a1 = (double)a/2;
+          	double b1 = (double)b/2;
+            int result= (int)ceil(a1) + (int)ceil(b1);
+            printf("%d\n",result);
+        }
+    }
+    return 0;
+}

C/README.md

@@ -29,6 +29,14 @@
 * UNROLLED LINKED LIST
 * SKIP LIST
 
+#### STACKS
+
+* FIXED ARRAY STACK
+* DYNAMIC ARRAY STACK
+* LINKED STACK
+* MISC
+  * [Minimum bracket reversal for balanced expression](Data-Structures/STACKS/MISC-STACKS/minimum_bracket_reversal_for_balanced_expression.c)
+
 #### HEAPS
 
 * [1D ARRAYS USING HEAPS](Data-Structures/HEAPS/dynamicarray.c)

datastructures.md

@@ -133,6 +133,13 @@ Indexer for Data Structures Lover
 
 #### MISC STACKS
 
+##### Minimum bracket reversal for making brackets balanced
+
+* blog
+* docs
+* implementation
+  * [C](C/Data-Structures/STACKS/MISC-STACKS/minimum_bracket_reversal_for_balanced_expression.c)
+
 ##### TWO WAY STACK
 
 * blog