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1. Stack Operations (Array Implementation) #include #include #define MAX 100 int st[MAX]; int top = -1; void push(int x); int pop(); int peek(); void display(); void main() { int flag = 0; int c,p,q,r; while (flag == 0) { printf("MENU\n"); printf("1.Push\n2.Pop\n3.Peek\n4.Display\n5.Exit\n"); printf("Enter your choice\n"); scanf("%d",&c); switch(c) { case 1: printf("Enter an element\n"); scanf("%d",&p); push(p); printf("Element inserted into stack\n"); break; case 2: q = pop(); printf("Element %d has been poped\n",q); break; case 3: r = peek(); printf("Element at the top is %d",r); break; case 4: printf("Current Stack: "); display(); break; case 5: flag = -1; break; default: printf("Please enter a valid choice"); }
void push(int x) { if(top == (MAX-1)) { printf("Stack is full \n"); } else { top++; st[top] = x; } } int pop() { int temp; if(top == -1) { printf("Stack is empty \n"); return 0; } else { temp = st[top]; top--; return temp; } } int peek() { if(top == -1) { printf("No element to display \n"); return 0; } else { return st[top]; } } void display() { int i; for(i=0; i<=top; i++) { printf("%d ",st[i]);
else { top++; st[top] = x; } } int pop() { int temp; if(top == -1) { printf("Stack is empty\n"); return 0; } else { temp = st[top]; top--; return temp; } }
3. Stack Application (Parenthesis check) #include #include #include #define MAX 100 char st[MAX]; int top = -1; int flag = 0; void push(int x); int pop(); int checkbalanced(char s[30]); void main() { char s[30]; printf("Enter a string\n"); fgets(s, sizeof(s), stdin); flag = checkbalanced(s); if(flag == 0) { printf("Parenthesis are not balanced\n"); } else { printf("Parenthesis are balanced\n"); } } int checkbalanced(char s[30]) { int i,temp; int l = strlen(s); for(i=0; i
4. Stack Application (Infix to Postfix) #include #include #include #define MAX 100 char st[MAX]; int top = -1; void infixpostfix(char s[]); void push(char x); char pop(); int priority(char ch); void main() { char str[30]; printf("Enter an expression\n"); scanf("%s",str); infixpostfix(str); } void infixpostfix(char s[]) { char res[30]; char temp; int n = strlen(s); int i=0,j=0; while(i res[j] = pop(); j++; } temp = pop(); i++; } else if((s[i]>='A' && s[i]<='Z')||(s[i]>='a' && s[i]<='z')||(s[i]>='0' && s[i]<='9')) { res[j] = s[i]; i++; j++; } else if(s[i]=='+' || s[i]=='-' || s[i]=='' || s[i]=='/' || s[i]=='%') { while(((top!=-1) && (st[top]!='(')) && (priority(st[top])>=priority(s[i]))) { res[j]=pop(); j++; } push(s[i]); i++; } else { printf("Incorrect Expression\n"); exit(1); } } while((top!=-1) && (st[top]!='(')) { res[j]=pop(); j++; } res[j]='\0'; printf("Postfix Expression \n"); puts(res); } int priority(char ch) { if(ch=='%' || ch=='/' || ch=='') { return 2; } else if(ch=='+' || ch=='-') { return 1; } else {
5. Stack Application (Postfix Evaluation) #include #include #include #include #define MAX 100 char st[MAX]; int top = -1; void push(int x); int pop(); int posteval(char str[]); void main() { char s[30]; int p; printf("Enter postfix expression \n"); scanf("%s",s); p = posteval(s); printf("%d",p); } int posteval(char str[]) { int l,i; int op2,op1,val; l = strlen(str); for(i=0; i push(str[i]-'0'); } else { op2 = pop(); op1 = pop(); switch(str[i]) { case '+': val=op1+op2; break; case '-': val=op1-op2; break; case '': val=op1op2; break; case '/': val=op1/op2; break; case '%': val=op1%op2; break; } push(val); } } return pop(); } void push(int x) { if(top == (MAX-1)) { printf("Stack is full\n"); } else { top++; st[top] = x; } } int pop() { int temp; if(top == -1) { printf("Stack is empty\n"); return 0;
else if(t[k]==')') { t[k]='('; } } infixprefix(t); } void infixprefix(char s[]) { char res[30]; char pre[30]; char temp; int n = strlen(s); int i=0,j=0,l1,y=0; while(i='A' && s[i]<='Z')||(s[i]>='a' && s[i]<='z')||(s[i]>='0' && s[i]<='9')) { res[j] = s[i]; i++; j++; } else if(s[i]=='+' || s[i]=='-' || s[i]=='*' || s[i]=='/' || s[i]=='%') { while(((top!=-1) && (st[top]!='(')) && (priority(st[top])>=priority(s[i]))) { res[j]=pop(); j++; } push(s[i]); i++; } else
printf("Incorrect Expression\n"); exit(1); } } while((top!=-1) && (st[top]!='(')) { res[j]=pop(); j++; } res[j]='\0'; l1=strlen(res); for(i=l1-1;i>=0;i--) { pre[y] = res[i]; y++; } pre[y]='\0'; printf("Prefix expression \n"); puts(pre); } void reversed(char s1[]) { int l = strlen(s1); int j,i=0; for(j=l-1; j>=0;j--) { t[i]=s1[j]; i++; } } int priority(char ch) { if(ch=='%' || ch=='/' || ch=='*') { return 2; } else if(ch=='+' || ch=='-') { return 1; } else { return 0; } } void push(char x)
int preeval(char str[]) { int l,i; int op2,op1,val; l = strlen(str); for(i=l-1; i>=0; i--) { if(isdigit(str[i])) { push(str[i]-'0'); } else { op1 = pop(); op2 = pop(); switch(str[i]) { case '+': val=op1+op2; break; case '-': val=op1-op2; break; case '': val=op1op2; break; case '/': val=op1/op2; break; case '%': val=op1%op2; break; } push(val); } } return pop(); } void push(int x) { if(top == (MAX-1)) { printf("Stack is full\n"); } else { top++; st[top] = x;
int pop() { int temp; if(top == -1) { printf("Stack is empty\n"); return 0; } else { temp = st[top]; top--; return temp; } }
8. Queue Operations (Array Implementation) #include #define MAX 100 int queue[MAX]; int front=-1, rear=-1; void insert(int x); int del(); int peek(); void display(); int main() { int ch,val; do { printf("MENU\n");
int val; if(front==-1 || front>rear) { printf("Queue is empty\n"); return -1; } else { val = queue[front]; front++; if(front>rear) { front=rear=-1; } return val; } } int peek() { if(front==-1 || front>rear) { printf("Queue is empty\n"); return -1; } else { return queue[front]; } } void display() { int i; if(front==-1 || front>rear) { printf("Queue is empty\n"); } else { for(i=front; i<=rear; i++) { printf("%d ",queue[i]); } } printf("\n"); }
