Question

C Programming Language

Problem Title: Introduction to Database

Database is a structurized method for data storage and perform operations related to
the data. There are Some simple operations that can be done by a database are Insert,
Alter, Delete, and Query.
There are N different integers stored. You are asked to create a database where you can
carry out the following 4 operations :
1. I X - this operation is insert operation, inserting X to the database.
2. A X Y - Alter operation that alter data with value of X to Y .
3. D X - this operation is to delete X-valued data from the database.
4. Q X - Query operation, to count number of data that less than or equal to X.
It is also guaranteed that :
1. Insert will add data that is not exist in the database.
2. Alter operation will change data in the database to a new data that is not exist in
the database.
3. Delete operation will delete data from the database. The value that want to be
deleted always exist.
4. At most 250 operations for Insert, Alter, and Delete.

Format Input

Input consists of two integers N and K - number of data and number of operation. The
next line contains N integers as the initial data stored in the database. Then followed by
K lines each contains an operation command (I, A, D, or Q) and followed by an integer
X for operation I, D, Q or two integers X and Y for A operation.

Format Output

For each Q operation, output an integer that shows number of data that does not exceed
the query.

Constraints

• 1 ≤ N ≤ 100000
• 1 ≤ K ≤ 10000
• 0 ≤ X , Y ≤ 1000000000

Sample Input & Output (standard input & output)

6 7

2 3 4 5 6 7

Q 4

Case #1: 3

I 1

Q 4

Case #2: 4

D 2

Q 4

Case #3: 3

A 6 2

Q 4

Case #4: 4

Answer 1

The source code is given below:

/*
* File: Database.c
*/

#include <stdio.h>
#include <stdlib.h>

#define N 100000
#define K 10000
#define X 1000000000
#define Y 1000000000

int n; /* Global variable for tracking total no of integers in the database*/
int data[N]; /*Global array of integers as database*/
int totQcase=0; /*Global variable for tracking total no of Query Case */
/* prototype declarations */
void insert(int x);
void alter(int x,int y);
void delete(int x);
void query(int x);
int main()
{
int k,x,y,i;
char op;
scanf("%d%d",&n,&k);// reading n and k
if((n>=1 && n<=N) && (k>=1 && k<=K))/* constraint check*/
{
for(i=0;i<n;i++)
scanf("%d",&data[i]); // reading initial data for data base

for(i=0;i<k;i++)
{
scanf(" %c",&op); // reading operation code

switch(op)
{
case 'I':
scanf("%d",&x); // reading operand x
if(x>=0 && x<=X)/* constraint check*/
{
insert(x); //insert operation called
}
else
printf("\ndata %d is out of range",x);
break;
case 'D':
scanf("%d",&x);// reading operand x
if(x>=0 && x<=X)/* constraint check*/
{
delete(x);//delete operation called
}
else
printf("\ndata %d is out of range",x);
break;
case 'Q':
scanf("%d",&x);// reading operand x
if(x>=0 && x<=X)/* constraint check*/
{
query(x);//query operation called
}
else
printf("\ndata %d is out of range",x);
break;
case 'A':
scanf("%d%d",&x,&y);// reading operand x and y
if((x>=0 && x<=X) && (y>=0 && y<=Y))/* constraint check*/
{
alter(x,y);//alter operation called
}
else
printf("\ndata %d or %d are out of range",x,y);
break;
}
}
}
else
printf("N or K is out of range");
printf("\n");
return (0);
}

void insert(int x)
{
int i;
for(i=0;i<n;i++){
if(data[i]==x)// if x found
break;
}
if(i==n)// if x not found
data[i]=x;// inserts x
  
n++;
  
}
void alter(int x,int y)
{
int i;
int xFound=0,yFound=0,xIndex=-1;
for(i=0;i<n;i++)
{
if(data[i]==x){// if x found
xFound=1;
xIndex=i;
break;
}
}
for(i=0;i<n;i++)
{
if(data[i]==y){// if y found
yFound=1;
break;
}
}
if(xFound && !yFound){ // if x found and y not found
data[xIndex]=y; // alters x with y
}
  
}
void delete(int x)
{
int i,pos=-1;
for(i=0;i<n;i++)
{
if(data[i]==x){ // if x found   
pos=i;
break;
}
}
if(pos!=-1){
for(i=pos;i<n-1;i++)
data[i]=data[i+1];//shifting operation
n--;
}
  
}
void query(int x)
{ int i,count=0;
totQcase++;
for(i=0;i<n;i++){
if(data[i]<=x)//counts data <= x
count++;
}
printf("\nCase #%d: %d",totQcase,count);//prints result
  
}

The source code screen shot is given below:

The output screen shot is given below: